I have gone through all the preliminary steps that you've listed to prepare to post a hijack-this log, and my machine seems to be clean of any viruses. I am running Windows XP Pro, and it is updated.
I'm not sure that corrupted files is my problem, but with my limited knowledge I've pretty much ruled out anything else.
Here is my Hijack-This Log: (thanks for your help )
Logfile of HijackThis v1.99.1
Scan saved at 10:23:25 PM, on 4/30/2005
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Ahead\InCD\InCDsrv.exe
c:\PROGRA~1\mcafee.com\vso\mcvsrte.exe
C:\Program Files\Common Files\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\PROGRA~1\McAfee.com\PERSON~1\MPFSERVICE.exe
c:\PROGRA~1\mcafee.com\vso\mcshield.exe
C:\PROGRA~1\mcafee.com\vso\mcvsshld.exe
c:\program files\mcafee.com\agent\mcagent.exe
c:\progra~1\mcafee.com\vso\mcvsescn.exe
C:\WINDOWS\system32\spool\drivers\w32x86\3\hpztsb07.exe
C:\Program Files\Ahead\InCD\InCD.exe
C:\Program Files\Java\jre1.5.0_02\bin\jusched.exe
C:\PROGRA~1\McAfee.com\PERSON~1\MpfTray.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Common Files\Intuit\QuickBooks\QBUpdate\qbupdate.exe
C:\PROGRA~1\McAfee.com\PERSON~1\MpfAgent.exe
C:\WINDOWS\explorer.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Documents and Settings\Emili\Desktop\HijackThis.exe
N3 - Netscape 7: user_pref("browser.search.defaultengine", "engine://C%3A%5CProgram%20Files%5CNetscape%5CNetscape%5Csearchplugins%5CSBWeb_01.src"); (C:\Documents and Settings\Emili\Application Data\Mozilla\Profiles\default\5pv9l94q.slt\prefs.js)
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O3 - Toolbar: McAfee VirusScan - {BA52B914-B692-46c4-B683-905236F6F655} - c:\progra~1\mcafee.com\vso\mcvsshl.dll
O4 - HKLM\..\Run: [VSOCheckTask] "c:\PROGRA~1\mcafee.com\vso\mcmnhdlr.exe" /checktask
O4 - HKLM\..\Run: [VirusScan Online] "c:\PROGRA~1\mcafee.com\vso\mcvsshld.exe"
O4 - HKLM\..\Run: [MCAgentExe] c:\PROGRA~1\mcafee.com\agent\mcagent.exe
O4 - HKLM\..\Run: [MCUpdateExe] C:\PROGRA~1\mcafee.com\agent\mcupdate.exe
O4 - HKLM\..\Run: [HPDJ Taskbar Utility] C:\WINDOWS\system32\spool\drivers\w32x86\3\hpztsb07.exe
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\system32\\NeroCheck.exe
O4 - HKLM\..\Run: [InCD] C:\Program Files\Ahead\InCD\InCD.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Program Files\Java\jre1.5.0_02\bin\jusched.exe
O4 - HKLM\..\Run: [MPFExe] C:\PROGRA~1\McAfee.com\PERSON~1\MpfTray.exe
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - Global Startup: Adobe Gamma Loader.exe.lnk = C:\Program Files\Common Files\Adobe\Calibration\Adobe Gamma Loader.exe
O4 - Global Startup: Adobe Reader Speed Launch.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: QuickBooks Update Agent.lnk = C:\Program Files\Common Files\Intuit\QuickBooks\QBUpdate\qbupdate.exe
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O9 - Extra 'Tools' menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe
O16 - DPF: {74D05D43-3236-11D4-BDCD-00C04F9A3B61} (HouseCall Control) - http://a840.g.akamai...all/xscan53.cab
O23 - Service: InCD File System Service (InCDsrv) - AHEAD Software - C:\Program Files\Ahead\InCD\InCDsrv.exe
O23 - Service: McAfee.com McShield (McShield) - Unknown owner - c:\PROGRA~1\mcafee.com\vso\mcshield.exe
O23 - Service: McAfee SecurityCenter Update Manager (mcupdmgr.exe) - McAfee, Inc - C:\PROGRA~1\McAfee.com\Agent\mcupdmgr.exe
O23 - Service: McAfee.com VirusScan Online Realtime Engine (MCVSRte) - McAfee, Inc - c:\PROGRA~1\mcafee.com\vso\mcvsrte.exe
O23 - Service: McAfee Personal Firewall Service (MpfService) - McAfee Corporation - C:\PROGRA~1\McAfee.com\PERSON~1\MPFSERVICE.exe