Virus win 32-trojan-gen

Slt,
Depuis hier, j'ai un problème de virus win 32 - trojan-gen. Je ne sais pas comment l'enlever. Si qq'un peut m'aider?
Merci d'avance
Logfile of HijackThis v1.99.1
Scan saved at 10:50:52, on 18/06/2006
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\RUNDLL32.EXE
C:\Program Files\Soft4Ever\looknstop\looknstop.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\RunDll32.exe
C:\Program Files\TechCity Solutions\AliceSAV\AliceAgent.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\RALINK\RT2500 USB Wireless LAN Card\Installer\WINXP\RaConfig2500.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\Program Files\OpenOffice.org 2.0\program\soffice.exe
C:\Program Files\OpenOffice.org 2.0\program\soffice.BIN
C:\Program Files\Executive Software\Diskeeper\DkService.exe
C:\WINDOWS\system32\nvsvc32.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\eMule\emule.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\Windows Media Player\wmplayer.exe
C:\Program Files\Alwil Software\Avast4\ashSimpl.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\eMule\config\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://www.google.fr/toolbar/ie8/sidebar.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.google.fr/?gws_rd=ssl
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://portail.free.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.google.fr/?gws_rd=ssl
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://www.google.fr/?gws_rd=ssl
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.google.fr/?gws_rd=ssl
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr/?gws_rd=ssl
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant = http://www.google.fr/toolbar/ie8/sidebar.html
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://www.google.fr/keyword/%s
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://sempron64/
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Alice ADSL
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Program Files\MSN Apps\ST\01.03.0000.1005\en-xu\stmain.dll
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.5000.1021\fr\msntb.dll
O3 - Toolbar: MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.5000.1021\fr\msntb.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [Look 'n' Stop] "C:\Program Files\Soft4Ever\looknstop\looknstop.exe" -auto
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [Cmaudio] RunDll32 cmicnfg.cpl,CMICtrlWnd
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [AliceSAV] C:\Program Files\TechCity Solutions\AliceSAV\AliceAgent.exe
O4 - Startup: OpenOffice.org 2.0.lnk = C:\Program Files\OpenOffice.org 2.0\program\quickstart.exe
O4 - Global Startup: RaConfig2500.lnk = C:\Program Files\RALINK\RT2500 USB Wireless LAN Card\Installer\WINXP\RaConfig2500.exe
O16 - DPF: {B79A53C0-1DAC-4636-BACE-FD086A7A79BF} (AdSignerLCContrl Class) - https://static.impots.gouv.fr/tdir/static/adpform/AdSignerADP.cab
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - "C:\PROGRA~1\MSNMES~1\msgrapp.dll" (file missing)
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - Unknown owner - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - Unknown owner - 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: Diskeeper - Executive Software International, Inc. - C:\Program Files\Executive Software\Diskeeper\DkService.exe
O23 - Service: GhostStartService - Symantec Corporation - C:\Program Files\Symantec\Norton Ghost 2003\GhostStartService.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe