Ciao... e grazie per la risposta!
sotto metto il file generato:

Logfile of HijackThis v1.99.1
Scan saved at 13.57.12, on 16/04/2007
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\Programmi\File comuni\Real\Update_OB\realsched.exe
C:\Programmi\Garzanti Linguistica\Hazon Clic\Hazon.exe
C:\Programmi\Spyware Terminator\SpywareTerminatorShield.exe
C:\Programmi\Google\GoogleToolbarNotifier\1.2.1128 .5462\GoogleToolbarNotifier.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Programmi\AntiVir PersonalEdition Classic\sched.exe
C:\Programmi\AntiVir PersonalEdition Classic\avguard.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\WINDOWS\system32\spool\drivers\w32x86\3\HPZipm1 2.exe
C:\WINDOWS\system32\Serutpac.exe
C:\Programmi\Spyware Terminator\sp_rsser.exe
C:\WINDOWS\System32\PAStiSvc.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\Wirelwss LAN Utility\tiwlnsvc.exe
C:\PROGRA~1\MICROS~2\Office10\OUTLOOK.EXE
C:\Programmi\Microsoft Office\Office10\WINWORD.EXE
C:\Programmi\Skype\Phone\Skype.exe
C:\Programmi\Skype\Plugin Manager\skypePM.exe
C:\Programmi\Internet Explorer\iexplore.exe
C:\Programmi\Hijackthis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
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
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
R3 - URLSearchHook: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.5.0_09\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\programmi\google\googletoolbar3.dll
O2 - BHO: Adobe PDF Conversion Toolbar Helper - {AE7CD045-E861-484f-8273-0445EE161910} - C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: Adobe PDF - {47833539-D0C5-4125-9FA8-0819E2EAAC93} - C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\programmi\google\googletoolbar3.dll
O4 - HKLM\..\Run: [TkBellExe] "C:\Programmi\File comuni\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [HAZON CLIC] C:\Programmi\Garzanti Linguistica\Hazon Clic\Hazon.exe -I
O4 - HKLM\..\Run: [SpywareTerminator] "C:\Programmi\Spyware Terminator\SpywareTerminatorShield.exe"
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKCU\..\Run: [swg] C:\Programmi\Google\GoogleToolbarNotifier\1.2.1128 .5462\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - Startup: Adobe Gamma.lnk.disabled
O8 - Extra context menu item: Converti destinazione link in Adobe PDF - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIECapture.html
O8 - Extra context menu item: Converti destinazione link in PDF esistente - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIEAppend.html
O8 - Extra context menu item: Converti in Adobe PDF - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIECapture.html
O8 - Extra context menu item: Converti in PDF esistente - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIEAppend.html
O8 - Extra context menu item: Converti link selezionati in Adobe PDF - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIECaptureSelLinks.html
O8 - Extra context menu item: Converti link selezionati in PDF esistente - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIEAppendSelLinks.html
O8 - Extra context menu item: Converti selezione a PDF esistente - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIEAppend.html
O8 - Extra context menu item: Converti selezione in Adobe PDF - res://C:\Programmi\Adobe\Acrobat 7.0\Acrobat\AcroIEFavClient.dll/AcroIECapture.html
O8 - Extra context menu item: Sothink SWF Catcher - C:\Programmi\File comuni\SourceTec\SWF Catcher\InternetExplorer.htm
O9 - Extra button: Sothink SWF Catcher - {E19ADC6E-3909-43E4-9A89-B7B676377EE3} - C:\Programmi\File comuni\SourceTec\SWF Catcher\InternetExplorer.htm
O9 - Extra 'Tools' menuitem: Sothink SWF Catcher - {E19ADC6E-3909-43E4-9A89-B7B676377EE3} - C:\Programmi\File comuni\SourceTec\SWF Catcher\InternetExplorer.htm
O11 - Options group: [INTERNATIONAL] International*
O14 - IERESET.INF: START_PAGE_URL=www.compital.com
O16 - DPF: {200B3EE9-7242-4EFD-B1E4-D97EE825BA53} (VerifyGMN Class) - http://h20270.www2.hp.com/ediags/gmn...taller_gmn.cab
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/S...in/AvSniff.cab
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Programmi\Yahoo!\Common\yinsthelper.dll
O16 - DPF: {60EFC337-15C2-4369-B2A0-3429B071D8B8} (Hewlett-Packard Printer Diagnostics) - http://h50203.www5.hp.com/HPISWeb/Cu...WebManager.CAB
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/S.../bin/cabsa.cab
O16 - DPF: {67DABFBF-D0AB-41FA-9C46-CC0F21721616} (DivXBrowserPlugin Object) - http://download.divx.com/player/DivXBrowserPlugin.cab
O16 - DPF: {6B75345B-AA36-438A-BBE6-4078B4C6984D} (HpProductDetection Class) - http://h20270.www2.hp.com/ediags/gmn...tDetection.cab
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://acs.pandasoftware.com/actives...ree/asinst.cab
O16 - DPF: {FE0BD779-44EE-4A4B-AA2E-743C63F2E5E6} (IWinAmpActiveX Class) - http://pdl.stream.aol.com/downloads/...ampx_en_dl.cab
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\FILECO~1\Skype\SKYPE4~1.DLL
O23 - Service: Adobe LM Service - Adobe Systems - C:\Programmi\File comuni\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: AntiVir PersonalEdition Classic Scheduler (AntiVirScheduler) - Avira GmbH - C:\Programmi\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: AntiVir PersonalEdition Classic Guard (AntiVirService) - AVIRA GmbH - C:\Programmi\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Programmi\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Macromedia Licensing Service - Unknown owner - C:\Programmi\File comuni\Macromedia Shared\Service\Macromedia Licensing.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\spool\drivers\w32x86\3\HPZipm1 2.exe
O23 - Service: Serutpac - Unknown owner - C:\WINDOWS\system32\Serutpac.exe
O23 - Service: ML-1610 Status Monitor Service (SM_ml1600_FUService) - Unknown owner - C:\Programmi\Samsung.exe (file missing)
O23 - Service: Spyware Terminator Realtime Shield Service (sp_rssrv) - Crawler.com - C:\Programmi\Spyware Terminator\sp_rsser.exe
O23 - Service: STI Simulator - Unknown owner - C:\WINDOWS\System32\PAStiSvc.exe
O23 - Service: TI Wlan Service (tiwlnsvc) - Unknown owner - C:\Programmi\Wirelwss LAN Utility\tiwlnsvc.exe