Il PC si blocca improvvisamente

[Cosimo77]

Salve a tutti, vorrei porre alla vs. attenzione il seguente quesito:

Ho un PC AMD Athlon XP 2600+, 512MB RAM, RADEON 9200 SERIES;
Da un po’ di giorni sto riscontrando un problema nel funzionamento del mio computer, il sintomo è molto strano: Mentre sto lavorando e senza che ci sia un particolare motivo all’improvviso il PC si inchioda rimanendo acceso, col cursore del mouse che non si muove più. Per rimettere tutto in funzione allora mi tocca letteralmente staccare e riattaccare la spina. Quale può essere il motivo di questo mal funzionamento e soprattutto come potrei fare per risolvere questo inconveniente... Potrebbe essere un virus? Chi saprebbe aiutarmi?

Grazie per la vs. cortesia!

[Cosimo77]

Qualcuno mi saprebbe aiutare per vedere se il mio logfile è ok?

Vi posto il logfile:

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\System32\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Programmi\a-squared Anti-Dialer\a2service.exe
C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe
C:\WINDOWS\system32\RegService.exe
C:\Programmi\Firebird\Firebird_2_0\bin\fbguard.exe
C:\Programmi\File comuni\Microsoft Shared\VS7Debug\mdm.exe
C:\Programmi\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
C:\PROGRA~1\NORTON~1\SPEEDD~1\nopdb.exe
C:\WINDOWS\System32\TUProgSt.exe
C:\PROGRA~1\SPEEDB~2\VideoAcceleratorService.exe
C:\PROGRA~1\AVG\AVG8\avgemc.exe
C:\PROGRA~1\AVG\AVG8\avgrsx.exe
C:\PROGRA~1\AVG\AVG8\avgnsx.exe
C:\Programmi\AVG\AVG8\avgcsrvx.exe
C:\Programmi\Firebird\Firebird_2_0\bin\fbserver.ex e
C:\WINDOWS\system32\wscntfy.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\SPEEDB~2\VideoAcceleratorEngine.exe
C:\WINDOWS\SOUNDMAN.EXE
C:\PROGRA~1\AVG\AVG8\avgtray.exe
C:\Programmi\Spybot - Search & Destroy\TeaTimer.exe
C:\Programmi\SpeedBit Video Accelerator\VideoAccelerator.exe
C:\documents and settings\utente\impostazioni locali\dati applicazioni\sgiua.exe
C:\Programmi\HSDPA USB Modem\USB Modem.exe
C:\Programmi\Internet Explorer\iexplore.exe
C:\Programmi\File comuni\Microsoft Shared\Windows Live\WLLoginProxy.exe
C:\Documents and Settings\Utente\Desktop\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://search.virgilio.it/search/home/index.html
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.libero.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.alice.it
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer fornito da Alice
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Int ernet Settings,ProxyOverride = local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
R3 - URLSearchHook: (no name) - *{CFBFAE00-17A6-11D0-99CB-00C04FD64497} - (no file)
R3 - URLSearchHook: (no name) - *{EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
R3 - URLSearchHook: AVG Security Toolbar BHO - {A3BC75A2-1F87-4686-AA43-5347D756017C} - C:\Programmi\AVG\AVG8\Toolbar\IEToolbar.dll
R3 - URLSearchHook: Yahoo! Toolbar con blocco Pop-Up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O2 - BHO: Skype add-on (mastermind) - {22BF413B-C6D2-4d91-82A9-A0F997BA588C} - C:\Programmi\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O2 - BHO: WormRadar.com IESiteBlocker.NavFilter - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - C:\Programmi\AVG\AVG8\avgssie.dll
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.6.0_04\bin\ssv.dll
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Programmi\File comuni\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Programmi\MSN Apps\ST\01.03.0000.1005\en-xu\stmain.dll
O2 - BHO: SBCONVERT - {A1056498-D09A-41E4-864B-505EDD640D9E} - C:\Programmi\SpeedBit Video Downloader\Toolbar\SpeedBitVideoDownloader.dll
O2 - BHO: AVG Security Toolbar BHO - {A3BC75A2-1F87-4686-AA43-5347D756017C} - C:\Programmi\AVG\AVG8\Toolbar\IEToolbar.dll
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programmi\MSN Apps\MSN Toolbar\01.02.5000.1021\it\msntb.dll
O2 - BHO: GrabberObj Class - {FF7C3CF0-4B15-11D1-ABED-709549C10000} - C:\PROGRA~1\SPEEDB~1\Toolbar\grabber.dll
O3 - Toolbar: MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programmi\MSN Apps\MSN Toolbar\01.02.5000.1021\it\msntb.dll
O3 - Toolbar: Yahoo! Toolbar con blocco Pop-Up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O3 - Toolbar: AVG Security Toolbar - {CCC7A320-B3CA-4199-B1A6-9F516DD69829} - C:\Programmi\AVG\AVG8\Toolbar\IEToolbar.dll
O3 - Toolbar: SpeedBit Video Downloader - {0329E7D6-6F54-462D-93F6-F5C3118BADF2} - C:\Programmi\SpeedBit Video Downloader\Toolbar\SpeedBitVideoDownloader.dll
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [AVG8_TRAY] C:\PROGRA~1\AVG\AVG8\avgtray.exe
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Programmi\Spybot - Search & Destroy\TeaTimer.exe
O4 - HKCU\..\Run: [SpeedBitVideoAccelerator] C:\Programmi\SpeedBit Video Accelerator\VideoAccelerator.exe
O4 - HKCU\..\Run: [sgiua] "c:\documents and settings\utente\impostazioni locali\dati applicazioni\sgiua.exe" sgiua
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\Run: [Symantec NetDriver Warning] C:\PROGRA~1\SYMNET~1\SNDWarn.exe (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'Default user')
O4 - Global Startup: Digisoft AntiDialer.lnk = C:\Programmi\Digisoft AntiDialer\AntiDialer.exe
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Zoom &In - C:\WINDOWS\web\zoomin.htm
O8 - Extra context menu item: Zoom &Out - C:\WINDOWS\web\zoomout.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_04\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_04\bin\ssv.dll
O9 - Extra button: Skype - {77BF5300-1474-4EC7-9980-D32B190E9B07} - C:\Programmi\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O9 - Extra button: Ricerche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: Organizzatore ricerche - {9455301C-CF6B-11D3-A266-00C04F689C50} - C:\Programmi\File comuni\Microsoft Shared\Encarta Researcher\EROPROJ.DLL
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O10 - Unknown file in Winsock LSP: c:\progra~1\speedb~2\sblsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\speedb~2\sblsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\speedb~2\sblsp.dll
O14 - IERESET.INF: START_PAGE_URL=http://www.alice.it
O16 - DPF: {0B105630-3B1F-11D1-B443-00A0244D2920} (WebTreeCtrl Class) - http://www.cesimultimedia.it/XProdot.../WebTreeFX.cab
O16 - DPF: {0EB0E74A-2A76-4AB3-A7FB-9BD8C29F7F75} (CKAVWebScan Object) - http://www.kaspersky.com/kos/eng/par...an_unicode.cab
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Programmi\Yahoo!\Common\yinsthelper.dll
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://www.update.microsoft.com/wind...?1188240514704
O17 - HKLM\System\CCS\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CCS\Services\Tcpip\..\{18D763B0-4D4D-4468-9C09-5C43F4F5911D}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CCS\Services\Tcpip\..\{CD022564-AC1E-4FC6-B3D3-293F1B24EAF1}: NameServer = 193.70.152.25 193.70.192.25
O17 - HKLM\System\CS1\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CS2\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CS3\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O18 - Protocol: linkscanner - {F274614C-63F8-47D5-A4D1-FBDDE494F8D1} - C:\Programmi\AVG\AVG8\avgpp.dll
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\FILECO~1\Skype\SKYPE4~1.DLL
O20 - Winlogon Notify: avgrsstarter - C:\WINDOWS\SYSTEM32\avgrsstx.dll
O23 - Service: a-squared Anti-Dialer Service (a2AntiDialer) - Emsi Software GmbH - C:\Programmi\a-squared Anti-Dialer\a2service.exe
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: AVG Free8 E-mail Scanner (avg8emc) - AVG Technologies CZ, s.r.o. - C:\PROGRA~1\AVG\AVG8\avgemc.exe
O23 - Service: AVG Free8 WatchDog (avg8wd) - AVG Technologies CZ, s.r.o. - C:\PROGRA~1\AVG\AVG8\avgwdsvc.exe
O23 - Service: Communication Modem Device Manager II - Unknown owner - C:\WINDOWS\system32\RegService.exe
O23 - Service: Firebird Guardian - DefaultInstance (FirebirdGuardianDefaultInstance) - FirebirdSQL Project - C:\Programmi\Firebird\Firebird_2_0\bin\fbguard.exe
O23 - Service: Firebird Server - DefaultInstance (FirebirdServerDefaultInstance) - FirebirdSQL Project - C:\Programmi\Firebird\Firebird_2_0\bin\fbserver.ex e
O23 - Service: Norton Unerase Protection (NProtectService) - Symantec Corporation - C:\Programmi\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
O23 - Service: Speed Disk service - Symantec Corporation - C:\PROGRA~1\NORTON~1\SPEEDD~1\nopdb.exe
O23 - Service: TuneUp Drive Defrag Service (TuneUp.Defrag) - TuneUp Software - C:\WINDOWS\System32\TuneUpDefragService.exe
O23 - Service: TuneUp Program Statistics Service (TuneUp.ProgramStatisticsSvc) - TuneUp Software - C:\WINDOWS\System32\TUProgSt.exe
O23 - Service: VideoAcceleratorService - Speedbit Ltd. - C:\PROGRA~1\SPEEDB~2\VideoAcceleratorService.exe
O24 - Desktop Component 0: (no name) - file:///C:/DOCUME~1/Utente/IMPOST~1/Temp/msohtml1/01/clip_image001.jpg
O24 - Desktop Component 1: (no name) - file:///C:/DOCUME~1/Utente/IMPOST~1/Temp/msohtml1/01/clip_image002.jpg

--

[Conetti]

Il log non è completo.
Hosta il log su MegaUpload e scrivi, nel tuo prossimo post, il link da cui scaricarlo
Grazie

[Cosimo77]

Ciao, scusami ma non essendo proprio un esperto di computer, non saprei come caricare il file su MegaUpload... Ti rimando nel forum il logfile completo... Spero che in questo modo vada bene...
A presto! Cosimo.

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 20.08.01, on 10/09/2009
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
Boot mode: Normal

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\winlogon.exe
C:\WINDOWS\system32\services.exe
C:\WINDOWS\system32\lsass.exe
C:\WINDOWS\System32\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Programmi\a-squared Anti-Dialer\a2service.exe
C:\WINDOWS\system32\RegService.exe
C:\Programmi\Firebird\Firebird_2_0\bin\fbguard.exe
C:\Programmi\File comuni\Microsoft Shared\VS7Debug\mdm.exe
C:\Programmi\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
C:\PROGRA~1\NORTON~1\SPEEDD~1\nopdb.exe
C:\WINDOWS\System32\TUProgSt.exe
C:\PROGRA~1\SPEEDB~2\VideoAcceleratorService.exe
C:\Programmi\Firebird\Firebird_2_0\bin\fbserver.ex e
C:\WINDOWS\system32\wscntfy.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\SOUNDMAN.EXE
C:\Programmi\SpeedBit Video Accelerator\VideoAccelerator.exe
C:\documents and settings\utente\impostazioni locali\dati applicazioni\sgiua.exe
C:\PROGRA~1\SPEEDB~2\VideoAcceleratorEngine.exe
C:\Programmi\HSDPA USB Modem\USB Modem.exe
C:\Documents and Settings\Utente\Desktop\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://search.virgilio.it/search/home/index.html
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.libero.it/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.alice.it
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer fornito da Alice
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
R3 - URLSearchHook: Yahoo! Toolbar con blocco Pop-Up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O2 - BHO: Skype add-on (mastermind) - {22BF413B-C6D2-4d91-82A9-A0F997BA588C} - C:\Programmi\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O2 - BHO: (no name) - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - (no file)
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.6.0_04\bin\ssv.dll
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Programmi\File comuni\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Programmi\MSN Apps\ST\01.03.0000.1005\en-xu\stmain.dll
O2 - BHO: SBCONVERT - {A1056498-D09A-41E4-864B-505EDD640D9E} - C:\Programmi\SpeedBit Video Downloader\Toolbar\SpeedBitVideoDownloader.dll
O2 - BHO: (no name) - {A3BC75A2-1F87-4686-AA43-5347D756017C} - (no file)
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programmi\MSN Apps\MSN Toolbar\01.02.5000.1021\it\msntb.dll
O2 - BHO: GrabberObj Class - {FF7C3CF0-4B15-11D1-ABED-709549C10000} - C:\PROGRA~1\SPEEDB~1\Toolbar\grabber.dll
O3 - Toolbar: MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Programmi\MSN Apps\MSN Toolbar\01.02.5000.1021\it\msntb.dll
O3 - Toolbar: Yahoo! Toolbar con blocco Pop-Up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O3 - Toolbar: (no name) - {CCC7A320-B3CA-4199-B1A6-9F516DD69829} - (no file)
O3 - Toolbar: SpeedBit Video Downloader - {0329E7D6-6F54-462D-93F6-F5C3118BADF2} - C:\Programmi\SpeedBit Video Downloader\Toolbar\SpeedBitVideoDownloader.dll
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Programmi\Spybot - Search & Destroy\TeaTimer.exe
O4 - HKCU\..\Run: [SpeedBitVideoAccelerator] C:\Programmi\SpeedBit Video Accelerator\VideoAccelerator.exe
O4 - HKCU\..\Run: [sgiua] "c:\documents and settings\utente\impostazioni locali\dati applicazioni\sgiua.exe" sgiua
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\Run: [Symantec NetDriver Warning] C:\PROGRA~1\SYMNET~1\SNDWarn.exe (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'Default user')
O4 - Global Startup: Digisoft AntiDialer.lnk = C:\Programmi\Digisoft AntiDialer\AntiDialer.exe
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Zoom &In - C:\WINDOWS\web\zoomin.htm
O8 - Extra context menu item: Zoom &Out - C:\WINDOWS\web\zoomout.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_04\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_04\bin\ssv.dll
O9 - Extra button: Skype - {77BF5300-1474-4EC7-9980-D32B190E9B07} - C:\Programmi\Skype\Toolbars\Internet Explorer\SkypeIEPlugin.dll
O9 - Extra button: Ricerche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: Organizzatore ricerche - {9455301C-CF6B-11D3-A266-00C04F689C50} - C:\Programmi\File comuni\Microsoft Shared\Encarta Researcher\EROPROJ.DLL
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\msmsgs.exe
O10 - Unknown file in Winsock LSP: c:\progra~1\speedb~2\sblsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\speedb~2\sblsp.dll
O10 - Unknown file in Winsock LSP: c:\progra~1\speedb~2\sblsp.dll
O14 - IERESET.INF: START_PAGE_URL=http://www.alice.it
O16 - DPF: {0B105630-3B1F-11D1-B443-00A0244D2920} (WebTreeCtrl Class) - http://www.cesimultimedia.it/XProdot.../WebTreeFX.cab
O16 - DPF: {0EB0E74A-2A76-4AB3-A7FB-9BD8C29F7F75} (CKAVWebScan Object) - http://www.kaspersky.com/kos/eng/par...an_unicode.cab
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Programmi\Yahoo!\Common\yinsthelper.dll
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://www.update.microsoft.com/wind...?1188240514704
O17 - HKLM\System\CCS\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CCS\Services\Tcpip\..\{18D763B0-4D4D-4468-9C09-5C43F4F5911D}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CS1\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CS2\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O17 - HKLM\System\CS3\Services\Tcpip\..\{0EB320DA-AD53-473A-87AB-4789BDE87A31}: NameServer = 151.99.125.2,194.243.154.62
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\FILECO~1\Skype\SKYPE4~1.DLL
O20 - Winlogon Notify: avgrsstarter - C:\WINDOWS\
O23 - Service: a-squared Anti-Dialer Service (a2AntiDialer) - Emsi Software GmbH - C:\Programmi\a-squared Anti-Dialer\a2service.exe
O23 - Service: Ati HotKey Poller - Unknown owner - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: Communication Modem Device Manager II - Unknown owner - C:\WINDOWS\system32\RegService.exe
O23 - Service: Firebird Guardian - DefaultInstance (FirebirdGuardianDefaultInstance) - FirebirdSQL Project - C:\Programmi\Firebird\Firebird_2_0\bin\fbguard.exe
O23 - Service: Firebird Server - DefaultInstance (FirebirdServerDefaultInstance) - FirebirdSQL Project - C:\Programmi\Firebird\Firebird_2_0\bin\fbserver.ex e
O23 - Service: Norton Unerase Protection (NProtectService) - Symantec Corporation - C:\Programmi\Norton SystemWorks\Norton Utilities\NPROTECT.EXE
O23 - Service: Speed Disk service - Symantec Corporation - C:\PROGRA~1\NORTON~1\SPEEDD~1\nopdb.exe
O23 - Service: TuneUp Drive Defrag Service (TuneUp.Defrag) - TuneUp Software - C:\WINDOWS\System32\TuneUpDefragService.exe
O23 - Service: TuneUp Program Statistics Service (TuneUp.ProgramStatisticsSvc) - TuneUp Software - C:\WINDOWS\System32\TUProgSt.exe
O23 - Service: VideoAcceleratorService - Speedbit Ltd. - C:\PROGRA~1\SPEEDB~2\VideoAcceleratorService.exe
O24 - Desktop Component 0: (no name) - file:///C:/DOCUME~1/Utente/IMPOST~1/Temp/msohtml1/01/clip_image001.jpg
O24 - Desktop Component 1: (no name) - file:///C:/DOCUME~1/Utente/IMPOST~1/Temp/msohtml1/01/clip_image002.jpg

--
End of file - 9748 bytes

[Conetti]

Ecco il log completo è questo
Per caricare i file su MegaUpload devi andare sull'home page del sito, selezionare il tuo file cliccando sul pulsante Sfoglia e, dopo aver immesso una descrizione del file, cliccare sul pulsante Invia: il file viene caricato e ti viene rilasciato il link da cui effettuare il download
Ciò ti può servire per una prossima volta
Per quanto riguarda il tuo problema Fixa con HiJackThis le seguenti voci:

O2 - BHO: (no name) - {3CA2F312-6F6E-4B53-A66E-4E65E497C8C0} - (no file)
O2 - BHO: (no name) - {A3BC75A2-1F87-4686-AA43-5347D756017C} - (no file)
O3 - Toolbar: (no name) - {CCC7A320-B3CA-4199-B1A6-9F516DD69829} - (no file)

Carica il seguente file (C:\documents and settings\utente\impostazioni locali\dati applicazioni\sgiua.exe) su VirusTotal e scrivi, nel tuo prossimo post, il log generato dal sito: non riesco a capire se questa voce sia riconducibile ad un malware o sia legittima.
Disinstalla l'applicazione SpeedBit Video Accelerator e software ad essa legati: questo software porta nel Pc numerosi malware.
Al termine esegui una pulizia del S.O. con CCleaner e sempre con questo software correggi i problemi del Registro di Sistema cliccando sul pulsante Registro.
Successivamente esegui una scansione con l'antivirus e con Spybot Search & Destroy ed elimina eventuali voci rilevate.
Esegui tutti gli aggiornamenti disponibili da Windows Update.
Riavvia il Pc e dimmi come va

[Guizzardi]

Con che frequenza hai il problema?

Potrebbe anche essere la RAM.

Puoi provare qualche programmino di test della RAM ma di solito, se hai due moduli installati (p.e. due da 256Mb) toglierne uno e vedere per un certo periodo se non si verifica più il difetto (anche solo lasciandolo acceso). Poi lo sostituisci lasciando solo l'altro modulo. Se il difetto si ripresenta individui la RAM compromessa.

Se hai un solo modulo allora diventa più difficile anche se a giudicare dai componenti hardware che elenchi mi sembra un PC datato e un modulo RAM in più non gli farebbe male.