please post here you hijackthis log (download hijackthis: http://www.spywareinfoforum.com/~merijn/downloads.html)
Logfile of HijackThis v1.99.1 Scan saved at 4:33:13 PM, on 2/1/2006 Platform: Windows XP SP2 (WinNT 5.01.2600) MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180) 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:\Program Files\Microsoft Windows OneCare Live\Antivirus\MSMPSVC.exe C:\Program Files\Microsoft Windows OneCare Live\Antivirus\MpEng.exe C:\WINDOWS\System32\svchost.exe C:\WINDOWS\system32\spoolsv.exe C:\WINDOWS\SYSTEM32\Ati2evxx.exe C:\WINDOWS\Explorer.EXE C:\Program Files\ewido anti-malware\ewidoctrl.exe C:\Program Files\ewido anti-malware\ewidoguard.exe C:\Program Files\Hewlett-Packard\Toolbox\StatusClient\StatusClient.exe C:\Program Files\Microsoft Windows OneCare Live\winssnotify.exe C:\Program Files\ATI Multimedia\main\ATIDtct.EXE C:\Program Files\Hewlett-Packard\Toolbox\jre\bin\javaw.exe C:\Program Files\Microsoft Windows OneCare Live\Firewall\mpssvc.exe C:\Program Files\Microsoft Windows OneCare Live\winss.exe C:\Program Files\ewido anti-malware\SecuritySuite.exe C:\Program Files\Internet Explorer\iexplore.exe C:\Documents and Settings\Dale F\My Documents\Unzipped\hijackthis\HijackThis.exe C:\WINDOWS\system32\HPBPRO.EXE O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar1.dll O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll O4 - HKLM\..\Run: [TomcatStartup 2.5] C:\Program Files\Hewlett-Packard\Toolbox\hpbpsttp.exe O4 - HKLM\..\Run: [StatusClient 2.6] C:\Program Files\Hewlett-Packard\Toolbox\StatusClient\StatusClient.exe /auto O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\system32\NvMcTray.dll,NvTaskbarInit O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup O4 - HKLM\..\Run: [ATICCC] "C:\Program Files\ATI Technologies\ATI.ACE\cli.exe" runtime -Delay O4 - HKLM\..\Run: [OneCareUI] "C:\Program Files\Microsoft Windows OneCare Live\winssnotify.exe" O4 - HKCU\..\Run: [ATI DeviceDetect] C:\Program Files\ATI Multimedia\main\ATIDtct.EXE O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000 O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe (file missing) O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe (file missing) O16 - DPF: {13EC55CF-D993-475B-9ACA-F4A384957956} (Controller Class) - https://www.windowsonecare.com/install/cli/0.8.0794.48/WinSSWebAgent.CAB O16 - DPF: {4ED9DDF0-7479-4BBE-9335-5A1EDB1D8A21} - http://download.mcafee.com/molbin/shared/mcinsctl/4,0,0,101/mcinsctl.cab O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/microsoftupdate/v6/V5Controls/en/x86/client/muweb_site.cab?1138077755046 O16 - DPF: {88D8E8B7-A33B-4417-A385-8373484D43ED} (InstallHelper Class) - file://C:\DOCUME~1\DALEF~1\LOCALS~1\Temp\ThereInstallHelper.dll O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe O23 - Service: ewido security suite control - ewido networks - C:\Program Files\ewido anti-malware\ewidoctrl.exe O23 - Service: ewido security suite guard - ewido networks - C:\Program Files\ewido anti-malware\ewidoguard.exe O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe O23 - Service: MSMPSVC - Unknown owner - C:\Program Files\Microsoft Windows OneCare Live\Antivirus\MSMPSVC.exe" -n 4 (file missing) O23 - Service: NVIDIA Driver Helper Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe O23 - Service: Pml Driver HPZ12 - HP - C:\WINDOWS\system32\HPZipm12.exe O23 - Service: Symantec Network Drivers Service (SNDSrvc) - Unknown owner - C:\Program Files\Common Files\Symantec Shared\SNDSrvc.exe (file missing) Hope I did this right.
how does your computer shutdown? Does the whole windows system freeze? Please check you RAM for example with memtest86: http://www.memtest86.com/