Infecte par trojan,help me!!

bonjour
j ai un pb de trojan avec des pages de pub qui s ouvre sans cesse
assez galere ad aware,spybot les trouves,les supprimes,mais ils reviennent a chaque fois
y a t il quelq un qui peut m aider svp??
j ai fait un scan ijackthis voici mon rapport :
Logfile of HijackThis v1.99.1
Scan saved at 00:40:11, on 27/04/2007
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:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\PROGRA~1\INCRED~1\bin\IMApp.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WLLoginProxy.exe
C:\Documents and Settings\guillaume bourgain\Bureau\test.exe.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = https://www.bing.com/?FORM=TOOLBR&cc=fr&toHttps=1&redig=4527FFF1C12746FC9EDB535C75E80ECC
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.free.fr/freebox/index.html
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.free.fr/freebox/index.html
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.free.fr/freebox/index.html
R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn0\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn0\yt.dll
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:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: (no name) - {6BD159F9-4942-484C-B8AE-66D281BC26D5} - C:\WINDOWS\system32\vtsqp.dll (file missing)
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: (no name) - {9DED2B32-743B-47EB-874C-28AECF2A268D} - C:\WINDOWS\system32\khfghig.dll (file missing)
O2 - BHO: Windows Live Toolbar Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Windows Live Toolbar - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn0\yt.dll
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [ATIPTA] C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKCU\..\Run: [IncrediMail] C:\PROGRA~1\INCRED~1\bin\IncMail.exe /c
O8 - Extra context menu item: &Windows Live Search - res://C:\Program Files\Windows Live Toolbar\msntb.dll/search.htm
O8 - Extra context menu item: Add to Windows &Live Favorites - https://onedrive.live.com/?id=favorites
O8 - Extra context menu item: Ouvrir dans un nouvel onglet d'arrière-plan - res://C:\Program Files\Windows Live Toolbar\Components\fr-fr\msntabres.dll.mui/229?bfcdabb6e49c4220aad9253aa1819e62
O8 - Extra context menu item: Ouvrir dans un nouvel onglet de premier plan - res://C:\Program Files\Windows Live Toolbar\Components\fr-fr\msntabres.dll.mui/230?bfcdabb6e49c4220aad9253aa1819e62
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
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: avast! Antivirus - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: AVG Anti-Spyware Guard - Anti-Malware Development a.s. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe