Grazie per l'aiuto.
Ho avuto finalmente il tempo per eseguire punto per punto quanto consigliatomi.
Sono arrivata al punto 4, poichè con i precedenti non sono riuscita a risolvere il problema, ossia il pc si blocca ancora per diversi minuti continui (anche 5/10).
Riporto qui di seguito il log nella sua interezza, risultante dal programma HJT che ho lanciato poco fà. Spero di ricevere presto vostre risposte. Grazie ancora.


Logfile of HijackThis v1.99.1
Scan saved at 22.46.45, on 19/03/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16414)

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\Ati2evxx.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Programmi\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\Programmi\Kaspersky Lab\Kaspersky Internet Security 6.0\avp.exe
C:\WINDOWS\eHome\ehRecvr.exe
C:\WINDOWS\eHome\ehSched.exe
C:\Apps\Softex\OmniPass\Omniserv.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\File comuni\Ulead Systems\DVD\ULCDRSvr.exe
C:\Programmi\Sonic\DigitalMedia LE v7\MyDVD LE\USBDeviceService.exe
C:\WINDOWS\system32\dllhost.exe
C:\Apps\Softex\OmniPass\OPXPApp.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\GOTOSO~1\VADERE~1\Vaderetro_oe.exe
C:\Programmi\Java\jre1.5.0_04\bin\jusched.exe
C:\WINDOWS\sm56hlpr.exe
C:\WINDOWS\RTHDCPL.EXE
C:\Programmi\QuickTime\qttask.exe
C:\Programmi\ScanSoft\OmniPageSE2.0\OpwareSE2.exe
C:\Apps\Softex\OmniPass\scureapp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\WINDOWS\ehome\ehtray.exe
C:\WINDOWS\eHome\ehmsas.exe
C:\Programmi\Sonic\DigitalMedia LE v7\MyDVD LE\DetectorApp.exe
C:\Programmi\digicomt\Michelangelo USB ADSL\CnxDslTb.exe
c:\Programmi\ATI Technologies\ATI.ACE\CLI.EXE
C:\Programmi\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\Programmi\Kaspersky Lab\Kaspersky Internet Security 6.0\avp.exe
C:\APPS\SMP\SmpSys.exe
c:\Programmi\ATI Technologies\ATI.ACE\cli.exe
c:\Programmi\ATI Technologies\ATI.ACE\cli.exe
C:\Programmi\Messenger\msmsgs.exe
C:\hijackthis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://format.packardbell.com/cgi-bi...e=6&key=SEARCH
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.videoaction-online.com/ashop
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
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
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Packard Bell
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Programmi\Spybot - Search & Destroy\SDHelper.dll
O3 - Toolbar: Easy-WebPrint - {327C2873-E90D-4c37-AA9D-10AC9BABA46C} - C:\Programmi\Canon\Easy-WebPrint\Toolband.dll
O4 - HKLM\..\Run: [Vade Retro Outlook Express] "C:\PROGRA~1\GOTOSO~1\VADERE~1\Vaderetro_oe.ex e"
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Programmi\Java\jre1.5.0_04\bin\jusched.exe
O4 - HKLM\..\Run: [SMSERIAL] sm56hlpr.exe
O4 - HKLM\..\Run: [RTHDCPL] RTHDCPL.EXE
O4 - HKLM\..\Run: [QuickTime Task] "C:\Programmi\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [PHIME2002ASync] C:\WINDOWS\system32\IME\TINTLGNT\TINTSETP.EXE /SYNC
O4 - HKLM\..\Run: [PHIME2002A] C:\WINDOWS\system32\IME\TINTLGNT\TINTSETP.EXE /IMEName
O4 - HKLM\..\Run: [OpwareSE2] "C:\Programmi\ScanSoft\OmniPageSE2.0\OpwareSE2.exe "
O4 - HKLM\..\Run: [OmniPass] C:\Apps\Softex\OmniPass\scureapp.exe
O4 - HKLM\..\Run: [ISUSScheduler] "C:\Programmi\File comuni\InstallShield\UpdateService\issch.exe" -start
O4 - HKLM\..\Run: [ISUSPM Startup] C:\PROGRA~1\FILECO~1\INSTAL~1\UPDATE~1\ISUSPM.exe -startup
O4 - HKLM\..\Run: [IMJPMIG8.1] "C:\WINDOWS\IME\imjp8_1\IMJPMIG.EXE" /Spoil /RemAdvDef /Migration32
O4 - HKLM\..\Run: [High Definition Audio Property Page Shortcut] HDAShCut.exe
O4 - HKLM\..\Run: [ehTray] C:\WINDOWS\ehome\ehtray.exe
O4 - HKLM\..\Run: [DetectorApp] C:\Programmi\Sonic\DigitalMedia LE v7\MyDVD LE\DetectorApp.exe
O4 - HKLM\..\Run: [CnxDslTaskBar] "C:\Programmi\digicomt\Michelangelo USB ADSL\CnxDslTb.exe"
O4 - HKLM\..\Run: [ATICCC] "c:\Programmi\ATI Technologies\ATI.ACE\CLIStart.exe"
O4 - HKLM\..\Run: [Alcmtr] ALCMTR.EXE
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Programmi\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKLM\..\Run: [AVP] "C:\Programmi\Kaspersky Lab\Kaspersky Internet Security 6.0\avp.exe"
O4 - HKCU\..\Run: [SmpcSys] C:\APPS\SMP\SmpSys.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Programmi\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [BgMonitor_{79662E04-7C6C-4d9f-84C7-88D8A56B10AA}] "C:\Programmi\File comuni\Ahead\Lib\NMBgMonitor.exe"
O4 - Global Startup: Microsoft Office.lnk = C:\Programmi\Microsoft Office\Office10\OSA.EXE
O8 - Extra context menu item: Add to Anti-Banner - C:\Programmi\Kaspersky Lab\Kaspersky Internet Security 6.0\ie_banner_deny.htm
O8 - Extra context menu item: Aggiungi all'elenco di stampa Easy-WebPrint - res://C:\Programmi\Canon\Easy-WebPrint\Resource.dll/RC_AddToList.html
O8 - Extra context menu item: Anteprima Easy-WebPrint - res://C:\Programmi\Canon\Easy-WebPrint\Resource.dll/RC_Preview.html
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O8 - Extra context menu item: Stampa ad alta velocità Easy-WebPrint - res://C:\Programmi\Canon\Easy-WebPrint\Resource.dll/RC_HSPrint.html
O8 - Extra context menu item: Stampa Easy-WebPrint - res://C:\Programmi\Canon\Easy-WebPrint\Resource.dll/RC_Print.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.5.0_04\bin\npjpi150_04.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.5.0_04\bin\npjpi150_04.dll
O9 - Extra button: Web Anti-Virus statistics - {1F460357-8A94-4D71-9CA3-AA4ACF32ED8E} - C:\Programmi\Kaspersky Lab\Kaspersky Internet Security 6.0\scieplugin.dll
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
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
O11 - Options group: [INTERNATIONAL] International*
O14 - IERESET.INF: START_PAGE_URL=file://C:\APPS\IE\offline\it.htm
O16 - DPF: {0EB0E74A-2A76-4AB3-A7FB-9BD8C29F7F75} (CKAVWebScan Object) - http://www.kaspersky.com/kos/eng/par...an_unicode.cab
O20 - AppInit_DLLs: C:\PROGRA~1\KASPER~1\KASPER~1.0\adialhk.dll
O20 - Winlogon Notify: klogon - C:\WINDOWS\system32\klogon.dll
O20 - Winlogon Notify: OPXPGina - C:\Apps\Softex\OmniPass\opxpgina.dll
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: AVG Anti-Spyware Guard - Anti-Malware Development a.s. - C:\Programmi\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: Kaspersky Internet Security 6.0 (AVP) - Unknown owner - C:\Programmi\Kaspersky Lab\Kaspersky Internet Security 6.0\avp.exe" -r (file missing)
O23 - Service: Softex OmniPass Service (omniserv) - Softex Inc. - C:\Apps\Softex\OmniPass\Omniserv.exe
O23 - Service: Ulead Burning Helper (UleadBurningHelper) - Ulead Systems, Inc. - C:\Programmi\File comuni\Ulead Systems\DVD\ULCDRSvr.exe
O23 - Service: USBDeviceService - Unknown owner - C:\Programmi\Sonic\DigitalMedia LE v7\MyDVD LE\USBDeviceService.exe