est ce un virus qui est la cause de mes soucis?

bonjour tt le monde!
j'ai un petit probleme.. il se trouve que je lorsque je telecharge qqchose.. que se soit un film, un zip, ou un prog, et ceci avec firefox et iexplorer, un message d 'erreur apparait et me dis que firefox doit fermer car il a rencontré un probleme et patatipatata..(on connais tous )
merci de votre aide
kissou ;-)

oki je tente de réinstaller.. tien en attendant

Logfile of HijackThis v1.99.1
Scan saved at 17:51:55, on 23.01.2006
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:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
D:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\ewido anti-malware\ewidoctrl.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Java\jre1.5.0_06\bin\jusched.exe
C:\WINDOWS\System32\LVCOMSX.EXE
D:\Program Files\Logitech\Video\LogiTray.exe
C:\Program Files\Messenger\MSMSGS.EXE
C:\Program Files\MSN Messenger\MsnMsgr.Exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\Pinnacle\Shared Files\Programs\Scheduler\PCLEScheduler.exe
C:\WINDOWS\system32\wscntfy.exe
D:\Program Files\Logitech\Video\FxSvr2.exe
D:\Jeux\steam\steam.exe
C:\Program Files\Spybot - Search & Destroy\SpybotSD.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Documents and Settings\jojo\Bureau\HijackThis.exe

O2 - BHO: (no name) - {00DBDAC8-4691-4797-8E6A-7C6AB89BC441} - C:\WINDOWS\system32\tuvww.dll (file missing)
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:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O4 - HKLM\..\Run: [TrojanScanner] C:\Program Files\Trojan Remover\Trjscan.exe
O4 - HKLM\..\Run: [iTunesHelper] "D:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Program Files\Java\jre1.5.0_06\bin\jusched.exe
O4 - HKLM\..\Run: [LVCOMSX] C:\WINDOWS\System32\LVCOMSX.EXE
O4 - HKLM\..\Run: [LogitechVideoRepair] D:\Program Files\Logitech\Video\ISStart.exe
O4 - HKLM\..\Run: [LogitechVideoTray] D:\Program Files\Logitech\Video\LogiTray.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\MSMSGS.EXE" /background
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [VoipBuster] "C:\Program Files\VoipBuster.com\VoipBuster\VoipBuster.exe" -nosplash -minimized
O4 - HKCU\..\Run: [Steam] "D:\Jeux\steam\Steam.exe" -silent
O4 - HKCU\..\Run: [LogitechSoftwareUpdate] "D:\Program Files\Logitech\Video\ManifestEngine.exe" boot
O4 - Startup: Registration-PCTV.lnk = C:\Program Files\Pinnacle\Pinnacle PCTV\ERegister\RegTool.exe
O4 - Global Startup: Pinnacle Scheduler.lnk = ?
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://D:\PROGRA~1\MICROS~1\OFFICE11\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: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_06\bin\ssv.dll
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - D:\PROGRA~1\MICROS~1\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: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/window [...] 7704003750
O16 - DPF: {B38870E4-7ECB-40DA-8C6A-595F0A5519FF} (MsnMessengerSetupDownloadControl Class) - http://messenger.msn.com/download/ [...] loader.cab
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - "C:\PROGRA~1\MSNMES~1\msgrapp.dll" (file missing)
O20 - Winlogon Notify: tuvww - tuvww.dll (file missing)
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\System32\Ati2evxx.exe
O23 - Service: ewido security suite control - ewido networks - C:\Program Files\ewido anti-malware\ewidoctrl.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: iPodService - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: NT Net Driver (NtNav) (NtNav) - Unknown owner - C:\WINDOWS\system32\netnav.exe (file missing)