Virus bloque Internet ?

Bonjour,

j'essaie de dépanner le portable de mon beau-frère qui, depuis quelques jours, ne peut plus surfer sur le web, ni accéder à ses mails via Outlook Express. Pourtant, la connexion est ouverte, et EMule fonctionne.
Suspectant un virus ou un malware, j'ai passé successivement :
- Adaware (trouvé juste un cookie, supprimé)
- Spybot (trouvé 2 entrées de registre à pb, semblant inhiber antivirus et firewall, corrigées)
- AVG Anti-Spyware (rien trouvé)
Puis, j'ai désinstallé Norton (périmé !!!) et installé Avast (y compris update).
Avast m'a trouvé 2 fichiers contenant Win32NetSky-BD [wrm], que j'ai mis en quarantaine.
Par acquit de conscience, j'ai passé ensuite les outils de nettoyage de ce worm de Symantec et de Kaspersky, qui n'ont plus rien trouvé.
Tout semble maintenant propre, or le problème d'Internet nest toujourslà, sans aucun changement.
Quelqu'un a-t-il une idée pour avancer sur ce problème ?
Merci d'avance.

Configuration: Windows XP
Internet Explorer 6.0

A toutes fins utiles, je joins un log HiJackThis :
Logfile of HijackThis v1.99.1
Scan saved at 11:48:02, on 06/02/2007
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:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
C:\Program Files\WIDCOMM\Logiciel Bluetooth\bin\btwdins.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\Program Files\Sunbelt Software\Personal Firewall\kpf4gui.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\HPQ\IAM\bin\asghost.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Program Files\Java\jre1.5.0_04\bin\jusched.exe
C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
C:\Program Files\HPQ\HP ProtectTools Security Manager\PTHOSTTR.EXE
C:\WINDOWS\system32\dla\tfswctrl.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\hpq\HP Wireless Assistant\HP Wireless Assistant.exe
C:\Program Files\HPQ\Quick Launch Buttons\EabServr.exe
C:\Program Files\BroadJump\Client Foundation\CFD.exe
C:\PROGRA~1\CLUB-I~1\LECOMP~1\SMARTB~1\MotiveSB.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\HPQ\Shared\hpqwmi.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\WIDCOMM\Logiciel Bluetooth\BTTray.exe
C:\Program Files\Club-Internet\Le Compagnon Club\bin\mpbtn.exe
C:\Program Files\Club-Internet\Lanceur\lanceur.exe
C:\Program Files\Zapu\Zapu\wDivi.exe
C:\WINDOWS\system32\wuauclt.exe
C:\Documents and Settings\Administrateur\Mes documents\Kit Momo\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = res://C:\Program Files\Copernic Agent\CopernicAgentExt.rdl/INTEGRATION_BAND_SEARCHBAR_HTML
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.club-internet.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.hp.com
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Internet Explorer avec Club-Internet
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: (no name) - {BE89472C-B803-4D1D-9A9A-0A63660E0FE3} - C:\PROGRA~1\COPERN~1\COPERN~1.DLL
R3 - URLSearchHook: Share Accelerator Toolbar - {f5c93451-2609-4723-a053-5c19516be1a8} - C:\Program Files\Share_Accelerator\tbShar.dll
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: DriveLetterAccess - {5CA3D70E-1895-11CF-8E15-001234567890} - C:\WINDOWS\system32\dla\tfswshx.dll
O2 - BHO: WebManager Class - {D5792AA9-D373-4039-8670-2CDAB6A71F15} - C:\Program Files\BitDownload\TorrentManager.dll
O2 - BHO: HP Credential Manager for ProtectTools - {DF21F1DB-80C6-11D3-9483-B03D0EC10000} - C:\Program Files\HPQ\IAM\Bin\ItIeAddIN.dll
O3 - Toolbar: Copernic Agent - {F2E259E8-0FC8-438C-A6E0-342DD80FA53E} - C:\Program Files\Copernic Agent\CopernicAgentExt.dll
O3 - Toolbar: Share Accelerator Toolbar - {f5c93451-2609-4723-a053-5c19516be1a8} - C:\Program Files\Share_Accelerator\tbShar.dll
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Program Files\Java\jre1.5.0_04\bin\jusched.exe
O4 - HKLM\..\Run: [ATIPTA] C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe
O4 - HKLM\..\Run: [PTHOSTTR] C:\Program Files\HPQ\HP ProtectTools Security Manager\PTHOSTTR.EXE /Start
O4 - HKLM\..\Run: [UpdateManager] "C:\Program Files\Fichiers communs\Sonic\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [dla] C:\WINDOWS\system32\dla\tfswctrl.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [hpWirelessAssistant] C:\Program Files\hpq\HP Wireless Assistant\HP Wireless Assistant.exe
O4 - HKLM\..\Run: [eabconfg.cpl] C:\Program Files\HPQ\Quick Launch Buttons\EabServr.exe /Start
O4 - HKLM\..\Run: [CognizanceTS] rundll32.exe C:\PROGRA~1\HPQ\IAM\Bin\AsTsVcc.dll,RegisterModule
O4 - HKLM\..\Run: [Cpqset] C:\Program Files\HPQ\Default Settings\cpqset.exe
O4 - HKLM\..\Run: [WatchDog] C:\Program Files\InterVideo\DVD Check\DVDCheck.exe
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [mouseElf] C:\PROGRA~1\SCROLL~1\MouseElf.EXE
O4 - HKLM\..\Run: [BJCFD] C:\Program Files\BroadJump\Client Foundation\CFD.exe
O4 - HKLM\..\Run: [Motive SmartBridge] C:\PROGRA~1\CLUB-I~1\LECOMP~1\SMARTB~1\MotiveSB.exe
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - Startup: Club Internet.lnk = C:\Program Files\Club-Internet\Lanceur\lanceur.exe
O4 - Startup: Zapu Acceleration Engine.lnk = C:\Program Files\Zapu\Zapu\wincm.exe
O4 - Startup: Zapu.lnk = C:\Program Files\Zapu\Zapu\wDivi.exe
O4 - Global Startup: BTTray.lnk = ?
O4 - Global Startup: DVD Check.lnk = C:\Program Files\InterVideo\DVD Check\DVDCheck.exe
O4 - Global Startup: LE COMPAGNON CLUB.lnk = C:\Program Files\Club-Internet\Le Compagnon Club\bin\matcli.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O8 - Extra context menu item: Chercher avec Copernic Agent - res://C:\Program Files\Copernic Agent\CopernicAgentExt.rdl/INTEGRATION_MENU_SEARCHEXT
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O8 - Extra context menu item: Envoyer à &Bluetooth - C:\Program Files\WIDCOMM\Logiciel Bluetooth\btsendto_ie_ctx.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_04\bin\npjpi150_04.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_04\bin\npjpi150_04.dll
O9 - Extra button: (no name) - {193B17B0-7C9F-4D5B-AEAB-8D3605EFC084} - C:\PROGRA~1\COPERN~1\COPERN~1.EXE
O9 - Extra 'Tools' menuitem: Démarrer Copernic Agent - {193B17B0-7C9F-4D5B-AEAB-8D3605EFC084} - C:\PROGRA~1\COPERN~1\COPERN~1.EXE
O9 - Extra button: Copernic Agent - {688DC797-DC11-46A7-9F1B-445F4F58CE6E} - C:\PROGRA~1\COPERN~1\COPERN~1.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
O14 - IERESET.INF: START_PAGE_URL=http://www.hp.com
O20 - AppInit_DLLs: ASAPHook
O20 - Winlogon Notify: OneCard - C:\Program Files\HPQ\IAM\Bin\AsWlnPkg.dll
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - Unknown owner - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.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: AVG Anti-Spyware Guard - Anti-Malware Development a.s. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: Bluetooth Service (btwdins) - Broadcom Corporation. - C:\Program Files\WIDCOMM\Logiciel Bluetooth\bin\btwdins.exe
O23 - Service: HP WMI Interface (hpqwmi) - Hewlett-Packard Development Company, L.P. - C:\Program Files\HPQ\Shared\hpqwmi.exe
O23 - Service: Sunbelt Kerio Personal Firewall 4 (KPF4) - Sunbelt Software - C:\Program Files\Sunbelt Software\Personal Firewall\kpf4ss.exe