pagine internet si aprono da sole

[evolve3.0]

Ciao ho un problema davvero seccante e non riesco a risolvere.
Quando avvio internet per la prima volta mi si apre in automatico anche un'altra pagina (quella di default punta normalmente a yahoo) che punta su siti o porno o adultfinder o oldgames.
Ho provato di tutto, ho installato norton 2005, win patrol, spysubstract con cwshredder e microsoft antyspyware.
Cancellato qualcosa, sembra funzionare ma poi niente.
Avevo risolto una volta il problema dell'about blank come pagiona iniziale eliminando una dll che era stata installata da non so dove, ma non ricordo il programma con il quale avevo controllato le dll.
Vi allego anche il log di hijackthis.
Aiuto sono frustrato
grazie
Ciao
Evolve3.0

Logfile of HijackThis v1.99.1
Scan saved at 22.00.16, on 28/04/2005
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

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:\Programmi\File comuni\Symantec Shared\ccSetMgr.exe
C:\Programmi\File comuni\Symantec Shared\SNDSrvc.exe
C:\Programmi\File comuni\Symantec Shared\SPBBC\SPBBCSvc.exe
C:\Programmi\File comuni\Symantec Shared\ccEvtMgr.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\System32\CTsvcCDA.EXE
C:\Programmi\Norton AntiVirus\navapsvc.exe
C:\Programmi\Norton AntiVirus\IWP\NPFMntor.exe
C:\WINDOWS\System32\nvsvc32.exe
C:\Programmi\File comuni\Symantec Shared\CCPD-LC\symlcsvc.exe
C:\WINDOWS\system32\ZoneLabs\vsmon.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\System32\CTHELPER.EXE
C:\PROGRA~1\ZONELA~1\ZONEAL~1\zlclient.exe
C:\Programmi\NetLimiter\NetLimiter.exe
C:\Programmi\File comuni\Symantec Shared\ccApp.exe
C:\PROGRA~1\BILLPS~1\WINPAT~1\WinPatrol.exe
C:\WINDOWS\System32\GSICON.EXE
C:\WINDOWS\System32\dslagent.exe
C:\Programmi\Creative\MediaSource\Detector\CTDetec t.exe
C:\Program Files\interMute\SpySubtract\SpySub.exe
C:\Programmi\Microsoft AntiSpyware\gcasDtServ.exe
C:\Programmi\Internet Explorer\iexplore.exe
C:\Programmi\Messenger\msmsgs.exe
C:\Documents and Settings\CrOwBAR\Desktop\hijackthis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.yahoo.com/
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: NAV Helper - {BDF3E430-B101-42AD-A544-FADC6B084872} - C:\Programmi\Norton AntiVirus\NavShExt.dll
O3 - Toolbar: Norton AntiVirus - {42CDD1BF-3FFB-4238-8AD1-7859DF00B1D6} - C:\Programmi\Norton AntiVirus\NavShExt.dll
O4 - HKLM\..\Run: [CTHelper] CTHELPER.EXE
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\System32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [Zone Labs Client] C:\PROGRA~1\ZONELA~1\ZONEAL~1\zlclient.exe
O4 - HKLM\..\Run: [NetLimiter] C:\Programmi\NetLimiter\NetLimiter.exe /s
O4 - HKLM\..\Run: [QuickTime Task] "C:\Programmi\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [ccApp] "C:\Programmi\File comuni\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [SSC_UserPrompt] C:\Programmi\File comuni\Symantec Shared\Security Center\UsrPrmpt.exe
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [GSICONEXE] GSICON.EXE
O4 - HKLM\..\Run: [DSLAGENTEXE] dslagent.exe USB
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\System32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [gcasServ] "C:\Programmi\Microsoft AntiSpyware\gcasServ.exe"
O4 - HKLM\..\Run: [WinPatrol PLUS] C:\PROGRA~1\BILLPS~1\WINPAT~1\WinPatrol.exe
O4 - HKCU\..\Run: [Creative Detector] C:\Programmi\Creative\MediaSource\Detector\CTDetec t.exe /R
O4 - Global Startup: SpySubtract.lnk = C:\Program Files\interMute\SpySubtract\SpySub.exe
O16 - DPF: {0A5FD7C5-A45C-49FC-ADB5-9952547D5715} (Creative Software AutoUpdate) - http://www.creative.com/su-newocx/ocx/15011/CTSUEng.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{89683406-7D5F-4F6D-B5C2-E152FE94AD4B}: NameServer = 85.37.17.15 151.99.125.1
O21 - SSODL: SystemCheck2 - {54645654-2225-4455-44A1-9F4543D34545} - C:\WINDOWS\System32\vbsys2.dll
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccEvtMgr.exe
O23 - Service: Symantec Password Validation (ccPwdSvc) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccPwdSvc.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\ccSetMgr.exe
O23 - Service: Creative Service for CDROM Access - Creative Technology Ltd - C:\WINDOWS\System32\CTsvcCDA.EXE
O23 - Service: Norton AntiVirus Auto-Protect Service (navapsvc) - Symantec Corporation - C:\Programmi\Norton AntiVirus\navapsvc.exe
O23 - Service: Norton AntiVirus Firewall Monitor Service (NPFMntor) - Symantec Corporation - C:\Programmi\Norton AntiVirus\IWP\NPFMntor.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\System32\nvsvc32.exe
O23 - Service: SAVScan - Symantec Corporation - C:\Programmi\Norton AntiVirus\SAVScan.exe
O23 - Service: ScriptBlocking Service (SBService) - Symantec Corporation - C:\PROGRA~1\FILECO~1\SYMANT~1\SCRIPT~1\SBServ.exe
O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\SNDSrvc.exe
O23 - Service: Symantec SPBBCSvc (SPBBCSvc) - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\SPBBC\SPBBCSvc.exe
O23 - Service: Symantec Core LC - Symantec Corporation - C:\Programmi\File comuni\Symantec Shared\CCPD-LC\symlcsvc.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs Inc. - C:\WINDOWS\system32\ZoneLabs\vsmon.exe

[crazy.cat]

Elimina questa riga,cancella anche tutti i file temp di windows e i temporanei di internet.
O21 - SSODL: SystemCheck2 - {54645654-2225-4455-44A1-9F4543D34545} - C:\WINDOWS\System32\vbsys2.dll

Usa una qualche scansione online per controllare i virus oppure usa lo scangui,dalla modalità provvisoria, per fare una scansione migliore che con il norton
http://www.megalab.it/articoli.php?id=513