Ordinateur infecté !! besoin d'aide...

Bonjour,
Je ne peux pas installer d'antivirus, je pense que mon pc est infecté... Est-ce qu'un expert pourrait m'aider à analyser le rapport Hijackthis et me dire quoi faire pour me débarrasser des virus ?

Le voici :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 11:12:23, on 08/02/2010
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16945)
Boot mode: Normal

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:\Program Files\Windows Defender\MsMpEng.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Fichiers communs\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\VIA\VIAudioi\HDADeck\HDeck.exe
C:\WINDOWS\sm56hlpr.exe
C:\WINDOWS\system32\VTTimer.exe
C:\WINDOWS\system32\S3trayp.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Windows Defender\MSASCui.exe
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\Java\jre1.6.0_07\bin\jusched.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Nikon\PictureProject\NkbMonitor.exe
C:\Documents and Settings\robertb\Bureau\HiJackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://google.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://fr.msn.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://red.clientapps.yahoo.com/customize/fuji/defaults/su/*https://fr.yahoo.com/?p=us
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Adobe PDF Reader Link Helper - {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\jre1.6.0_07\bin\ssv.dll
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O4 - HKLM\..\Run: [HDAudDeck] C:\Program Files\VIA\VIAudioi\HDADeck\HDeck.exe 1
O4 - HKLM\..\Run: [SMSERIAL] C:\WINDOWS\sm56hlpr.exe
O4 - HKLM\..\Run: [VTTimer] VTTimer.exe
O4 - HKLM\..\Run: [S3Trayp] S3trayp.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [Windows Defender] "C:\Program Files\Windows Defender\MSASCui.exe" -masquer
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_07\bin\jusched.exe"
O4 - HKCU\..\Run: [Google Update] "C:\Documents and Settings\robertb\Local Settings\Application Data\Google\Update\GoogleUpdate.exe" /c
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\Run: [DWQueuedReporting] "C:\PROGRA~1\FICHIE~1\MICROS~1\DW\dwtrig20.exe" -t (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O4 - Global Startup: Lancement rapide d'Adobe Reader.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: NkbMonitor.exe.lnk = C:\Program Files\Nikon\PictureProject\NkbMonitor.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~3\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_07\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_07\bin\ssv.dll
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\OFFICE11\REFIEBAR.DLL
O9 - Extra button: PacificPoker4 - {94EDF7B4-4272-4af3-8F8B-4E2F68E225B7} - C:\PROGRA~1\PACIFI~1\pacificpoker.exe
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra button: Yahoo! Messenger - {E5D12C4E-7B4F-11D3-B5C9-0050045C3C96} - C:\PROGRA~1\Yahoo!\MESSEN~1\YPager.exe
O9 - Extra 'Tools' menuitem: Yahoo! Messenger - {E5D12C4E-7B4F-11D3-B5C9-0050045C3C96} - C:\PROGRA~1\Yahoo!\MESSEN~1\YPager.exe
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
O15 - Trusted Zone: *.canalplay.com (HKLM)
O15 - Trusted Zone: *.canalplusactive.com (HKLM)
O16 - DPF: {5C6698D9-7BE4-4122-8EC5-291D84DBD4A0} (Facebook Photo Uploader 4 Control) - http://upload.facebook.com/controls/FacebookPhotoUploader3.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O23 - Service: LVSrvLauncher - Logitech Inc. - C:\Program Files\Fichiers communs\LogiShrd\SrvLnch\SrvLnch.exe
O23 - Service: Windows Live Setup Service (WLSetupSvc) - Unknown owner - C:\Program Files\Windows Live\installer\WLSetupSvc.exe