Problemes avec Firefox et Internet Explorer

Effectivement, le deuxième point que tu invoques , me paraît suspect.
"- avec IE lorsque je fais une recherche de site par exemple sur google, ou yahoo (enfin peu importe), et que je clique sur le lien il me redirige vers des sites qui n'ont rien à voir (sites en anglais, commerciaux ou antispywre..) "

Fais ceci dans un premier temps:
https://leblogdeclaude.blogspot.com/2007/03/informatique-procdure-de-nettoyage.html
Fais ceci en second lieu:
https://leblogdeclaude.blogspot.com/2006/10/informatique-section-hijackthis.html

voici mon scan HijackThis :

Logfile of HijackThis v1.99.1
Scan saved at 20:02:39, on 11/03/2007
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\csrss.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\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
c:\program files\fichiers communs\logishrd\lvmvfm\LVPrcSrv.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\BroadJump\Client Foundation\CFD.exe
C:\Program Files\Java\jre1.5.0_11\bin\jusched.exe
C:\PROGRA~1\CLUB-I~1\LECOMP~1\SMARTB~1\MotiveSB.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\Program Files\Fichiers communs\LogiShrd\LComMgr\Communications_Helper.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
C:\WINDOWS\system32\nvsvc32.exe
C:\Program Files\Club-Internet\Lanceur\lanceur.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Fichiers communs\Ulead Systems\DVD\ULCDRSvr.exe
C:\WINDOWS\system32\wdfmgr.exe
C:\Program Files\club-internet\LE COMPAGNON CLUB\bin\mpbtn.exe
C:\Program Files\Fichiers communs\LogiShrd\LComMgr\LVComSX.exe
C:\WINDOWS\System32\alg.exe
C:\Program Files\Fichiers communs\Logishrd\LQCVFX\COCIManager.exe
C:\WINDOWS\System32\svchost.exe
D:\Hijack this\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://actus.sfr.fr
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Internet Explorer avec Club-Internet
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: e-Carte Bleue Browser Helper Object - {2E03C0FD-4C48-43A7-9A54-00240C70FF16} - C:\WINDOWS\system32\BhoECart.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_11\bin\ssv.dll
O2 - BHO: IeCatch2 Class - {A5366673-E8CA-11D3-9CD9-0090271D075B} - C:\PROGRA~1\FlashGet\jccatch.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: AcroIEToolbarHelper Class - {AE7CD045-E861-484f-8273-0445EE161910} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: Adobe PDF - {47833539-D0C5-4125-9FA8-0819E2EAAC93} - C:\Program Files\Adobe\Acrobat 6.0\Acrobat\AcroIEFavClient.dll
O3 - Toolbar: FlashGet Bar - {E0E899AB-F487-11D5-8D29-0050BA6940E3} - C:\PROGRA~1\FlashGet\fgiebar.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [Zone Labs Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKLM\..\Run: [KernelFaultCheck] %systemroot%\system32\dumprep 0 -k
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: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [DAEMON Tools-1033] "C:\Program Files\D-Tools\daemon.exe" -lang 1033
O4 - HKLM\..\Run: [BJCFD] C:\Program Files\BroadJump\Client Foundation\CFD.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.5.0_11\bin\jusched.exe"
O4 - HKLM\..\Run: [Motive SmartBridge] C:\PROGRA~1\CLUB-I~1\LECOMP~1\SMARTB~1\MotiveSB.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [LogitechCommunicationsManager] "C:\Program Files\Fichiers communs\LogiShrd\LComMgr\Communications_Helper.exe"
O4 - HKLM\..\Run: [LogitechQuickCamRibbon] "C:\Program Files\Logitech\QuickCam10\QuickCam10.exe" /hide
O4 - HKCU\..\Run: [NBJ] "D:\Ahead\Nero BackItUp\NBJ.exe"
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\1.2.1128.5462\GoogleToolbarNotifier.exe
O4 - Startup: Club Internet.lnk = C:\Program Files\Club-Internet\Lanceur\lanceur.exe
O4 - Global Startup: Docteur Club Internet.lnk = C:\Program Files\Club-Internet\Dr Club Internet\bin\matcli.exe
O4 - Global Startup: LE COMPAGNON CLUB.lnk = C:\Program Files\Club-Internet\LE COMPAGNON CLUB\bin\matcli.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~1\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Tout télécharger en utilisant FlashGet - C:\Program Files\FlashGet\jc_all.htm
O8 - Extra context menu item: Télécharger en utilisant FlashGet - C:\Program Files\FlashGet\jc_link.htm
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_11\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_11\bin\ssv.dll
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~1\OFFICE11\REFIEBAR.DLL
O9 - Extra button: FlashGet - {D6E814A0-E0C5-11d4-8D29-0050BA6940E3} - C:\PROGRA~1\FlashGet\flashget.exe
O9 - Extra 'Tools' menuitem: &FlashGet - {D6E814A0-E0C5-11d4-8D29-0050BA6940E3} - C:\PROGRA~1\FlashGet\flashget.exe
O9 - Extra button: Yahoo! Messenger - {E5D12C4E-7B4F-11D3-B5C9-0050045C3C96} - C:\Program Files\Yahoo!\Messenger\YahooMessenger.exe
O9 - Extra 'Tools' menuitem: Yahoo! Messenger - {E5D12C4E-7B4F-11D3-B5C9-0050045C3C96} - C:\Program Files\Yahoo!\Messenger\YahooMessenger.exe
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
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: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Logitech Process Monitor (LVPrcSrv) - Logitech Inc. - c:\program files\fichiers communs\logishrd\lvmvfm\LVPrcSrv.exe
O23 - Service: LVSrvLauncher - Logitech Inc. - C:\Program Files\Fichiers communs\LogiShrd\SrvLnch\SrvLnch.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: Ulead Burning Helper (UleadBurningHelper) - Ulead Systems, Inc. - C:\Program Files\Fichiers communs\Ulead Systems\DVD\ULCDRSvr.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Zone Labs Inc. - C:\WINDOWS\system32\ZoneLabs\vsmon.exe

fais ceci:
https://leblogdeclaude.blogspot.com/2007/03/informatique-procdure-navifix.html