Computer va in bambola sempre alla stessa ora

Salve forum,
ormai e' piu di una settimana che mi capita una cosa stranissima.
Io accendo il computer al mattino verso le 8,00: al pomeriggio verso le ore 15,30 (come se avessa un orologio, dopo tot ore di accensione) il computer va in bambola, ad esempio mi dice che la quarantena dell'antivirus e' piena, su internet non va piu', spariscono i preferiti, non si entra piu' in nessun programma perche' dice che non si e' inpossesso dei requisiti per poter entrare.
A questo punto allora facendo CTRL+ALT+CANC vado nel task manager e faccio arresta il sistema, perche' anche tramite il pulsante START non si riesce piu' a spegnere.
Una volta spento si riaccende normalmente e si lavora normalmente.
Tutto questo non capita se nel corso della giornata (prima delle 15,30) si spegne e si riaccende il computer, e' come se si azzerasse il tempo e ricominciasse a contare da zero.
Il mio sistema operativo e' windows 2000 professional. L'antivirus non rileva niente di particolare ed e' AVG a pagamento e anche l'anti spyware che e' spyware terminator non rileva niente.
Che cosa puo' essere capitato?
Come posso fare a risolvere il problema?
Ringrazio chinuque voglia darmi una mano.

Aziendapm

postaci il log di HijackThis

Scusate l'ignoranza, ma non ho capito che cosa devo postare...
Che cos'e' HijackThis ?

Scusate ancora...Aziendapm

Sono riuscita a fare qualcosa, ecco cosa sono riuscita a postare:

Logfile of HijackThis v1.99.1
Scan saved at 14.38.45, on 09/07/2007
Platform: Windows 2000 SP4 (WinNT 5.00.2195)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINNT\System32\smss.exe
C:\WINNT\system32\winlogon.exe
C:\WINNT\system32\services.exe
C:\WINNT\system32\lsass.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\system32\spoolsv.exe
C:\Programmi\Lavasoft\Ad-Aware 2007\aawservice.exe
C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe
C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
C:\PROGRA~1\Grisoft\AVG7\avgrssvc.exe
C:\PROGRA~1\Grisoft\AVG7\avgrssvc.exe
C:\WINNT\System32\svchost.exe
C:\Programmi\File comuni\Microsoft Shared\VS7Debug\mdm.exe
C:\WINNT\system32\regsvc.exe
C:\WINNT\system32\MSTask.exe
C:\Programmi\Spyware Terminator\sp_rsser.exe
C:\paghe\stserv\BIN\STRLCS.EXE
C:\Programmi\Symantec\LiveUpdate\ALUSchedulerSvc.exe
C:\PROGRA~1\Grisoft\AVG7\avgrssvc.exe
C:\WINNT\System32\WBEM\WinMgmt.exe
C:\WINNT\System32\mspmspsv.exe
C:\WINNT\system32\svchost.exe
C:\PROGRA~1\Grisoft\AVG7\avgfwsrv.exe
C:\paghe\stserv\BIN\STSERV.EXE
C:\paghe\stserv\BIN\strwatch.exe
C:\WINNT\Explorer.EXE
C:\Programmi\QuickTime\qttask.exe
C:\Programmi\Java\jre1.6.0_01\bin\jusched.exe
C:\Programmi\Spyware Terminator\SpywareTerminatorShield.exe
C:\PROGRA~1\Grisoft\AVG7\avgcc.exe
C:\WINNT\system32\ctfmon.exe
C:\Programmi\Kodak\Kodak EasyShare software\bin\EasyShare.exe
C:\Programmi\Kodak\KODAK Software Updater\7288971\Program\Kodak Software Updater.exe
C:\Programmi\WinZip\WZQKPICK.EXE
C:\Programmi\OpenOffice.org 2.0\program\soffice.exe
C:\Programmi\OpenOffice.org 2.0\program\soffice.BIN
C:\Programmi\Microsoft Office\Office10\OUTLOOK.EXE
C:\Programmi\Microsoft Office\Office10\WINWORD.EXE
C:\Programmi\Internet Explorer\iexplore.exe
C:\PROGRA~1\WINZIP\winzip32.exe
C:\Documents and Settings\PATRIZIA\Impostazioni locali\Temp\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.msn.it/
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = localhost
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
R3 - URLSearchHook: Yahoo! Toolbar - {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: Supporto di collegamento per Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\File comuni\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.6.0_01\bin\ssv.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\programmi\google\googletoolbar3.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINNT\System32\msdxm.ocx
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\programmi\google\googletoolbar3.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Programmi\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [Synchronization Manager] mobsync.exe /logon
O4 - HKLM\..\Run: [QuickTime Task] "C:\Programmi\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Programmi\Java\jre1.6.0_01\bin\jusched.exe"
O4 - HKLM\..\Run: [SpywareTerminator] "C:\Programmi\Spyware Terminator\SpywareTerminatorShield.exe"
O4 - HKLM\..\Run: [AVG7_CC] C:\PROGRA~1\Grisoft\AVG7\avgcc.exe /STARTUP
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Programmi\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKCU\..\Run: [ctfmon.exe] ctfmon.exe
O4 - Startup: OpenOffice.org 2.0.lnk = C:\Programmi\OpenOffice.org 2.0\program\quickstart.exe
O4 - Global Startup: Kodak EasyShare software.lnk = C:\Programmi\Kodak\Kodak EasyShare software\bin\EasyShare.exe
O4 - Global Startup: Kodak software updater.lnk = C:\Programmi\Kodak\KODAK Software Updater\7288971\Program\Kodak Software Updater.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Programmi\Microsoft Office\Office10\OSA.EXE
O4 - Global Startup: WinZip Quick Pick.lnk = C:\Programmi\WinZip\WZQKPICK.EXE
O8 - Extra context menu item: &Add animation to IncrediMail Style Box - C:\PROGRA~1\INCRED~1\bin\WebMenuImg.htm
O8 - Extra context menu item: Advanced Properties - http://www.unixmage.com/util/advprop.php3
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_01\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_01\bin\ssv.dll
O10 - Unknown file in Winsock LSP: c:\winnt\system32\avgfwafu.dll
O10 - Unknown file in Winsock LSP: c:\winnt\system32\avgfwafu.dll
O10 - Unknown file in Winsock LSP: c:\winnt\system32\avgfwafu.dll
O10 - Unknown file in Winsock LSP: c:\winnt\system32\avgfwafu.dll
O10 - Unknown file in Winsock LSP: c:\winnt\system32\avgfwafu.dll
O15 - Trusted Zone: http://www.190.it
O16 - DPF: {05CA9FB0-3E3E-4B36-BF41-0E3A5CAA8CD8} (Office Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=58813
O16 - DPF: {2BC66F54-93A8-11D3-BEB6-00105AA9B6AE} (Symantec AntiVirus scanner) - http://security.symantec.com/sscv6/Shar ... vSniff.cab
O16 - DPF: {42C559C0-2E84-11D5-A3C6-00010219529D} (siacapi-core-install) - https://www.unibanking.it/common/applet ... nstall.cab
O16 - DPF: {446A606F-1DAF-4EA1-A6E6-522883C44908} (libRegistry.clsRegistry) - https://www.unibanking.it/common/applet/libRegistry.CAB
O16 - DPF: {644E432F-49D3-41A1-8DD5-E099162EEEC5} (Symantec RuFSI Utility Class) - http://security.symantec.com/sscv6/Shar ... /cabsa.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftup ... 6814323830
O16 - DPF: {98672704-9BA2-4079-B29F-73AE18FEC65F} - http://www.1001-desktop.com/sfondiscreen12.exe
O16 - DPF: {9A9307A0-7DA4-4DAF-B042-5009F29E09E1} (ActiveScan Installer Class) - http://acs.pandasoftware.com/activescan ... asinst.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{DE73473B-9F91-4B1D-B9BD-993C695684E8}: NameServer = 151.99.125.2,151.99.250.2
O20 - Winlogon Notify: avgwlntf - C:\WINNT\SYSTEM32\avgwlntf.dll
O23 - Service: Ad-Aware 2007 Service (aawservice) - Lavasoft AB - C:\Programmi\Lavasoft\Ad-Aware 2007\aawservice.exe
O23 - Service: AVG7 Alert Manager Server (Avg7Alrt) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgamsvr.exe
O23 - Service: AVG7 Update Service (Avg7UpdSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgupsvc.exe
O23 - Service: AVG7 Resident Shield Service (AvgCoreSvc) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgrssvc.exe
O23 - Service: AVG Firewall (AVGFwSrv) - GRISOFT, s.r.o. - C:\PROGRA~1\Grisoft\AVG7\avgfwsrv.exe
O23 - Service: Servizio amministrativo di Gestione disco logico (dmadmin) - VERITAS Software Corp. - C:\WINNT\System32\dmadmin.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Programmi\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Kodak Camera Connection Software (KodakCCS) - Eastman Kodak Company - C:\WINNT\system32\drivers\KodakCCS.exe
O23 - Service: LiveUpdate - Symantec Corporation - C:\PROGRA~1\Symantec\LIVEUP~1\LUCOMS~1.EXE
O23 - Service: Smart Card Base Component Helper (SetScardSvrService) - Unknown owner - C:\WINNT\system32\SetScardSvrService.exe (file missing)
O23 - Service: Spyware Terminator Realtime Shield Service (sp_rssrv) - Crawler.com - C:\Programmi\Spyware Terminator\sp_rsser.exe
O23 - Service: Stratos - Unknown owner - C:\paghe\stserv\BIN\STSERV.EXE
O23 - Service: StratosLcServer - Unknown owner - C:\paghe\stserv\BIN\STRLCS.EXE
O23 - Service: StrWatch - Unknown owner - C:\paghe\stserv\BIN\strwatch.exe
O23 - Service: SymWMI Service (SymWSC) - Unknown owner - C:\Programmi\File comuni\Symantec Shared\Security Center\SymWSC.exe (file missing)
O23 - Service: Utilità di pianificazione di LiveUpdate automatico - Symantec Corporation - C:\Programmi\Symantec\LiveUpdate\ALUSchedulerSvc.exe

In attesa di risposta ringrazio ancora Aziendapm