Merci pour cette réponse rapide Jeroma et Bonne année à toi !
Bon je vais suivre à la lettre la procédure que tu me recommandes.
En attendant, voici le rapport HijackThis d'aujourd'hui
Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 15:05:08, on 01/01/2008
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16574)
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Fichiers communs\Symantec Shared\ccSvcHst.exe
C:\Program Files\Fichiers communs\Symantec Shared\AppCore\AppSvc32.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Fichiers communs\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\WIDCOMM\Logiciel Bluetooth\bin\btwdins.exe
C:\Program Files\Fichiers communs\LightScribe\LSSrvc.exe
C:\Program Files\Fichiers communs\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\WINDOWS\system32\nvsvc32.exe
C:\Program Files\Symantec\LiveUpdate\ALUSchedulerSvc.exe
C:\WINDOWS\system32\svchost.exe
C:\Program Files\Hewlett-Packard\Shared\hpqwmiex.exe
C:\Program Files\Java\jre1.6.0_03\bin\jusched.exe
C:\Program Files\hpq\HP Wireless Assistant\HP Wireless Assistant.exe
C:\WINDOWS\system32\RUNDLL32.EXE
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\HP\QuickPlay\QPService.exe
C:\Program Files\Hp\HP Software Update\HPWuSchd2.exe
C:\Program Files\Hewlett-Packard\HP Quick Launch Buttons\QlbCtrl.exe
C:\WINDOWS\system32\LVCOMSX.EXE
C:\Program Files\Logitech\Video\LogiTray.exe
C:\Program Files\ScanSoft\OmniPageSE2.0\OpwareSE2.exe
C:\Program Files\Adobe\Photoshop Album Edition Découverte\3.2\Apps\apdproxy.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Fichiers communs\Microsoft Shared\Works Shared\WkUFind.exe
C:\Program Files\Microsoft Office\OFFICE11\WINWORD.EXE
C:\Program Files\Fichiers communs\Symantec Shared\ccApp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Logitech\Video\FxSvr2.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Program Files\Microsoft Money\System\mnyexpr.exe
C:\Program Files\MSN Messenger\MsnMsgr.Exe
C:\Program Files\Microsoft ActiveSync\Wcescomm.exe
C:\Program Files\WIDCOMM\Logiciel Bluetooth\BTTray.exe
C:\PROGRA~1\MI3AA1~1\rapimgr.exe
C:\PROGRA~1\WIDCOMM\LOGICI~1\BTSTAC~1.EXE
C:\Program Files\Logitech\Desktop Messenger\8876480\Program\LogitechDesktopMessenger.exe
C:\PROGRA~1\HPQ\Shared\HPQTOA~1.EXE
C:\Program Files\HP\Digital Imaging\bin\hpqimzone.exe
C:\PROGRA~1\MICROS~3\OFFICE11\OUTLOOK.EXE
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\MSN Messenger\usnsvc.exe
C:\Program Files\MSN Messenger\livecall.exe
C:\Program Files\MyIE2\MyIE.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://g.msn.fr/0SEFRFR/SAOS01?FORM=TOOLBR
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://g.msn.fr/0SEFRFR/SAOS01?FORM=TOOLBR
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.orange.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://g.msn.fr/0SEFRFR/SAOS01?FORM=TOOLBR
R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://renewalcenter.symantec.com/ [...] 20Pavilion
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = localhost
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn0\yt.dll
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn0\yt.dll
O2 - BHO: Aide pour le lien d'Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Fichiers communs\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
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) - {243B17DE-77C7-46BF-B94B-0B5F309A0E64} - C:\Program Files\Microsoft Money\System\mnyside.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0_03\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\2.0.301.7164\swg.dll
O2 - BHO: Windows Live Toolbar Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O2 - BHO: (no name) - {FDD3B846-8D59-4ffb-8758-209B6AD74ACC} - (no file)
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O3 - Toolbar: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn0\yt.dll
O3 - Toolbar: Windows Live Toolbar - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\Windows Live Toolbar\msntb.dll
O3 - Toolbar: Easy-WebPrint - {327C2873-E90D-4c37-AA9D-10AC9BABA46C} - C:\Program Files\Canon\Easy-WebPrint\Toolband.dll
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: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_03\bin\jusched.exe"
O4 - HKLM\..\Run: [hpWirelessAssistant] C:\Program Files\hpq\HP Wireless Assistant\HP Wireless Assistant.exe
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\WINDOWS\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [nwiz] nwiz.exe /installquiet /nodetect
O4 - HKLM\..\Run: [High Definition Audio Property Page Shortcut] CHDAudPropShortcut.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [QPService] "C:\Program Files\HP\QuickPlay\QPService.exe"
O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\Hp\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [QlbCtrl] %ProgramFiles%\Hewlett-Packard\HP Quick Launch Buttons\QlbCtrl.exe /Start
O4 - HKLM\..\Run: [Cpqset] C:\Program Files\HPQ\Default Settings\cpqset.exe
O4 - HKLM\..\Run: [RecGuard] C:\Windows\SMINST\RecGuard.exe
O4 - HKLM\..\Run: [Reminder] C:\Windows\CREATOR\Remind_XP.exe
O4 - HKLM\..\Run: [LVCOMSX] C:\WINDOWS\system32\LVCOMSX.EXE
O4 - HKLM\..\Run: [LogitechVideoRepair] C:\Program Files\Logitech\Video\ISStart.exe
O4 - HKLM\..\Run: [LogitechVideoTray] C:\Program Files\Logitech\Video\LogiTray.exe
O4 - HKLM\..\Run: [OpwareSE2] "C:\Program Files\ScanSoft\OmniPageSE2.0\OpwareSE2.exe"
O4 - HKLM\..\Run: [Adobe Photo Downloader] "C:\Program Files\Adobe\Photoshop Album Edition Découverte\3.2\Apps\apdproxy.exe"
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [Microsoft Works Update Detection] C:\Program Files\Fichiers communs\Microsoft Shared\Works Shared\WkUFind.exe
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 - HKLM\..\Run: [Symantec PIF AlertEng] "C:\Program Files\Fichiers communs\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\PIFSvc.exe" /a /m "C:\Program Files\Fichiers communs\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\AlertEng.dll"
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [MoneyAgent] "C:\Program Files\Microsoft Money\System\mnyexpr.exe"
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [H/PC Connection Agent] "C:\Program Files\Microsoft ActiveSync\Wcescomm.exe"
O4 - HKCU\..\RunOnce: [] C:\Program Files\Internet Explorer\iexplore.exe http://www.symantec.com/techsupp/s [...] 7.000001cf
O4 - HKUS\S-1-5-19\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVICE LOCAL')
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')
O4 - Global Startup: BTTray.lnk = ?
O4 - Global Startup: Démarrage rapide de HP Photosmart Premier.lnk = C:\Program Files\Hp\Digital Imaging\bin\hpqthb08.exe
O4 - Global Startup: Google Updater.lnk = C:\Program Files\Google\Google Updater\GoogleUpdater.exe
O4 - Global Startup: Lancement rapide d'Adobe Reader.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O4 - Global Startup: Logitech Desktop Messenger.lnk = C:\Program Files\Logitech\Desktop Messenger\8876480\Program\LogitechDesktopMessenger.exe
O8 - Extra context menu item: &Windows Live Search - res://C:\Program Files\Windows Live Toolbar\msntb.dll/search.htm
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~3\OFFICE11\EXCEL.EXE/3000
O8 - Extra context menu item: Easy-WebPrint Ajouter à la Liste à Imprimer - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_AddToList.html
O8 - Extra context menu item: Easy-WebPrint Impression rapide - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_HSPrint.html
O8 - Extra context menu item: Easy-WebPrint Imprimer - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_Print.html
O8 - Extra context menu item: Easy-WebPrint Prévisualiser - res://C:\Program Files\Canon\Easy-WebPrint\Resource.dll/RC_Preview.html
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\jre1.6.0_03\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_03\bin\ssv.dll
O9 - Extra button: Create Mobile Favorite - {2EAF5BB1-070F-11D3-9307-00C04FAE2D4F} - C:\PROGRA~1\MI3AA1~1\INetRepl.dll
O9 - Extra button: (no name) - {2EAF5BB2-070F-11D3-9307-00C04FAE2D4F} - C:\PROGRA~1\MI3AA1~1\INetRepl.dll
O9 - Extra 'Tools' menuitem: Créer un Favori de l'appareil mobile... - {2EAF5BB2-070F-11D3-9307-00C04FAE2D4F} - C:\PROGRA~1\MI3AA1~1\INetRepl.dll
O9 - Extra button: (no name) - {85d1f590-48f4-11d9-9669-0800200c9a66} - C:\WINDOWS\bdoscandel.exe
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 - {85d1f590-48f4-11d9-9669-0800200c9a66} - C:\WINDOWS\bdoscandel.exe
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\OFFICE11\REFIEBAR.DLL
O9 - Extra button: @btrez.dll,-4015 - {CCA281CA-C863-46ef-9331-5C8D4460577F} - C:\Program Files\WIDCOMM\Logiciel Bluetooth\btsendto_ie.htm
O9 - Extra 'Tools' menuitem: @btrez.dll,-4017 - {CCA281CA-C863-46ef-9331-5C8D4460577F} - C:\Program Files\WIDCOMM\Logiciel Bluetooth\btsendto_ie.htm
O9 - Extra button: MoneySide - {E023F504-0C5A-4750-A1E7-A9046DEA8A21} - C:\Program Files\Microsoft Money\System\mnyside.dll
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
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://download.bitdefender.com/re [...] oscan8.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/ [...] wflash.cab
O18 - Protocol: bwfile-8876480 - {9462A756-7B47-47BC-8C80-C34B9B80B32B} - C:\Program Files\Logitech\Desktop Messenger\8876480\Program\GAPlugProtocol-8876480.dll
O23 - Service: Apple Mobile Device - Apple, Inc. - C:\Program Files\Fichiers communs\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: Bluetooth Service (btwdins) - Broadcom Corporation. - C:\Program Files\WIDCOMM\Logiciel Bluetooth\bin\btwdins.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: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: hpqwmiex - Hewlett-Packard Development Company, L.P. - C:\Program Files\Hewlett-Packard\Shared\hpqwmiex.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - c:\Program Files\Fichiers communs\InstallShield\Driver\1050\Intel 32\IDriverT.exe
O23 - Service: Service de l'iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Validation de mot de passe Symantec IS (ISPwdSvc) - Symantec Corporation - C:\Program Files\Norton Internet Security\isPwdSvc.exe
O23 - Service: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Fichiers communs\LightScribe\LSSrvc.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: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.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
--
End of file - 16019 bytes