Je suis infectée par des trojans

Bonjour,
Voila j' ai un gros souci ça fait plusieurs jours que je suis infecté par des trojans qui sortent de je ne sais pas où j' ai des Vundo , TrojanHorse , AdClicker , Trojan Low.Zones alors j' ai installé quelques petits programmes comme Spybot , Ad-Aware 2007 Pro , MalwareBytes Anti-Malware etc... Mon antivirus est Norton Internet Security 2007. Que dois-je faire ???

Déjà voici un scan HijackThis :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16:21, on 2008-06-06
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16640)
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\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Fichiers communs\Symantec Shared\ccSvcHst.exe
C:\Program Files\Fichiers communs\Symantec Shared\AppCore\AppSvc32.exe
D:\Programmes\Utilitaires\Ad-Aware\aawservice.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Symantec\LiveUpdate\ALUSchedulerSvc.exe
C:\Program Files\Fichiers communs\Symantec Shared\ccApp.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Windows Live\Messenger\msnmsgr.exe
C:\Program Files\Windows Live\Messenger\usnsvc.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Internet Explorer\iexplore.exe
D:\Programmes\Utilitaires\HijackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr/?gws_rd=ssl
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr/?ocid=iehp
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: (no name) - {1DFEF793-BFB7-40CB-BA5E-656E5915772B} - (no file)
O2 - BHO: (no name) - {1E8A6170-7264-4D0F-BEAE-D42A53123C75} - C:\Program Files\Fichiers communs\Symantec Shared\coShared\Browser\1.0\NppBho.dll
O2 - BHO: (no name) - {319A3B32-6A7A-4425-A036-3DEBD34E508D} - (no file)
O2 - BHO: (no name) - {510C6ED9-56BD-47A3-A029-2C7F326C5F73} - (no file)
O2 - BHO: (no name) - {5427F701-6685-4E31-8D69-5FEDF2025910} - (no file)
O2 - BHO: (no name) - {5F77729A-BC77-491B-8115-BEB78131639C} - (no file)
O2 - BHO: (no name) - {7399C6F0-F72F-41B6-B477-6EC9BB009D9F} - (no file)
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_06\bin\ssv.dll
O2 - BHO: (no name) - {7C0213FB-B35B-45FE-A6CF-2E675F2970C6} - (no file)
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: (no name) - {98E169FD-EF84-4263-AEDD-2322FFB14A7B} - (no file)
O2 - BHO: (no name) - {9ACC9C3A-A7B2-4193-91B7-39B2E7E01342} - (no file)
O2 - BHO: (no name) - {D220DC08-3FFA-4203-AD87-A2EAD4E638C5} - (no file)
O2 - BHO: (no name) - {D2A0AC18-C1B1-40BA-A304-1C53A2F38250} - (no file)
O2 - BHO: (no name) - {DBF87699-20FF-444C-A428-77A6FE872CBC} - (no file)
O2 - BHO: (no name) - {EC3C8CFC-2620-4509-9148-2E1BFC5AFFD3} - (no file)
O3 - Toolbar: Afficher Norton Toolbar - {90222687-F593-4738-B738-FBEE9C7B26DF} - C:\Program Files\Fichiers communs\Symantec Shared\coShared\Browser\1.0\UIBHO.dll
O4 - HKLM\..\Run: [ccApp] "C:\Program Files\Fichiers communs\Symantec Shared\ccApp.exe"
O4 - HKLM\..\Run: [osCheck] "C:\Program Files\Norton Internet Security\osCheck.exe"
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKUS\S-1-5-20\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVICE RÉSEAU')
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_06\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_06\bin\ssv.dll
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
O20 - Winlogon Notify: byxVliJC - byxVliJC.dll (file missing)
O23 - Service: Ad-Aware 2007 Service (aawservice) - Lavasoft - D:\Programmes\Utilitaires\Ad-Aware\aawservice.exe
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: Symantec Event Manager (ccEvtMgr) - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Settings Manager (ccSetMgr) - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\ccSvcHst.exe
O23 - Service: Symantec Lic NetConnect service (CLTNetCnService) - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\ccSvcHst.exe
O23 - Service: COM Host (comHost) - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\VAScanner\comHost.exe
O23 - Service: Validation de mot de passe Symantec IS (ISPwdSvc) - Symantec Corporation - C:\Program Files\Norton Internet Security\isPwdSvc.exe
O23 - Service: LiveUpdate - Symantec Corporation - C:\PROGRA~1\Symantec\LIVEUP~1\LUCOMS~1.EXE
O23 - Service: LiveUpdate Notice Service Ex (LiveUpdate Notice Ex) - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\ccSvcHst.exe
O23 - Service: LiveUpdate Notice Service - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\PIFSvc.exe
O23 - Service: Planificateur LiveUpdate automatique - Symantec Corporation - C:\Program Files\Symantec\LiveUpdate\ALUSchedulerSvc.exe
O23 - Service: Symantec Core LC - Unknown owner - C:\Program Files\Fichiers communs\Symantec Shared\CCPD-LC\symlcsvc.exe
O23 - Service: Symantec AppCore Service (SymAppCore) - Symantec Corporation - C:\Program Files\Fichiers communs\Symantec Shared\AppCore\AppSvc32.exe