Messages d'alerte intempestifs : à l'aide !...

Bonjour à tous
j'ai regulièrement des fenetres qui s'ouvrent avec des messages :

Microsoft inform you about a virus detection. Critical System Error !
the Windows registrery appears to be infected. Please go to regfixes.com to scan and repair the system registry


Message de SYSTEM ALERT STOP WINDOWS REQUIRES IMMEDIATE ATTENTION Windows has found CRITICAL SYSTEM ERRORS.To fix the errors please do the following :
1. Download Registry Cleaner from : www.winfix32.com
2. Install Registry Cleaner
3. Run Registry Cleaner
4. Reboot your computer
FAILURE TO ACT NOW MAY LEAD TO DATA LOSS AND CORRUPTION!

Message de SECURITY MONITOR à WINDOWS USER
Important Windows Security Bulletin
Buffer Overrun in MessengerService Allows Remote Code Execution
Virus Infection and unexpected Computer Shutdowns
Affected Software :
Microsoft Windows NT Workstation
Microsoft Windows NT Server 4.0
Microsoft Windows 2000
Microsoft Windows XP
Microsoft Windows Win98
Microsoft Windows Server 2003

Non Affected Software :
Microsoft Windows Millenium Edition

Your system is affected, download the patch from the address below !
FIRST TYPE THE ADDRESS BELOW INTO YOUR INTERNET BROWSER, THEN CLICK OK.
THE ADDRESS WILL DISAPPEAR ONCE YOU CLICK OK.
www.patchupdate.info

je suis sous Windows 2000 Pro
J'ai téléchargé un tas de logiciel anti virus (Avast) et un pare-feu (Jetico) et Spybot Search & Destroy mais cela semble ne pas suffire...

quelqu'un a t-il une solution à me proposer? (ci-dessous mon rapport HiJackThis)
merci d'avance

Logfile of Trend Micro HijackThis v2.0.0 (BETA)
Scan saved at 22:32:05, on 13/04/2007
Platform: Windows 2000 SP4 (WinNT 5.00.2195)
Boot mode: Normal

Running processes:
C:\WINNT\System32\smss.exe
C:\WINNT\system32\winlogon.exe
C:\WINNT\system32\services.exe
C:\WINNT\system32\lsass.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\system32\spoolsv.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\system32\nvsvc32.exe
C:\WINNT\system32\regsvc.exe
C:\WINNT\system32\MSTask.exe
C:\WINNT\System32\WBEM\WinMgmt.exe
C:\WINNT\system32\svchost.exe
C:\WINNT\Explorer.EXE
C:\Program Files\D-Link\AirPlus G\AirGCFG.exe
C:\Program Files\ANI\ANIWZCS2 Service\WZCSLDR2.exe
C:\Program Files\Jetico\Jetico Personal Firewall\fwsrv.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\WINNT\system32\internat.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\WINNT\system32\wuauclt.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\adslTV\vlc.exe
C:\jpfwall.exe
C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\~BCSEL~1.TMP\Setup.exe
C:\Documents and Settings\Administrator\Desktop\HiJackThis_v2.exe

R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Program Files\Spybot - Search & Destroy\SDHelper.dll
O3 - Toolbar: @msdxmLC.dll,-1@1033,&Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINNT\system32\msdxm.ocx
O3 - Toolbar: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll
O4 - HKLM\..\Run: [Synchronization Manager] mobsync.exe /logon
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE NvQTwk,NvCplDaemon initialize
O4 - HKLM\..\Run: [nwiz] nwiz.exe /installquiet
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [D-Link AirPlus G] C:\Program Files\D-Link\AirPlus G\AirGCFG.exe
O4 - HKLM\..\Run: [ANIWZCS2Service] C:\Program Files\ANI\ANIWZCS2 Service\WZCSLDR2.exe
O4 - HKLM\..\Run: [JeticoPFStartup] "C:\Program Files\Jetico\Jetico Personal Firewall\fwsrv.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKCU\..\Run: [internat.exe] internat.exe
O4 - HKUS\.DEFAULT\..\Run: [internat.exe] internat.exe (User 'Default user')
O4 - HKUS\.DEFAULT\..\RunOnce: [^SetupICWDesktop] C:\Program Files\Internet Explorer\Connection Wizard\icwconn1.exe /desktop (User 'Default user')
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
O9 - Extra button: Related - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - C:\WINNT\web\related.htm
O9 - Extra 'Tools' menuitem: Show &Related Links - {c95fe080-8f5d-11d2-a20b-00aa003c157a} - C:\WINNT\web\related.htm
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Program Files\Yahoo!\Common\yinsthelper.dll
O22 - SharedTaskScheduler: Browseui preloader - {438755C2-A8BA-11D1-B96B-00A0C90312E1} - C:\WINNT\system32\browseui.dll
O22 - SharedTaskScheduler: Component Categories cache daemon - {8C7461EF-2B13-11d2-BE35-3078302C2030} - C:\WINNT\system32\browseui.dll
O23 - Service: ANIWZCSd Service (ANIWZCSdService) - Alpha Networks Inc. - C:\Program Files\ANI\ANIWZCS2 Service\ANIWZCSdS.exe
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 - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
O23 - Service: Logical Disk Manager Administrative Service (dmadmin) - VERITAS Software Corp. - C:\WINNT\System32\dmadmin.exe
O23 - Service: Service de l'iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: NVIDIA Driver Helper Service (NVSvc) - NVIDIA Corporation - C:\WINNT\system32\nvsvc32.exe

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