Problème de pubs intempestives sur internet !

Bonjour,
j'ai un petit souci avec internet. Lorsque je me connecte, des pages de pubs s'ouvrent un peu tout le temps et n'importe quand. Voilà mon rapport Hijackthis :
Logfile of HijackThis v1.99.1
Scan saved at 23:45:11, on 03/02/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.5730.0011)

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\spoolsv.exe
C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
C:\WINDOWS\System32\nvsvc32.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Microsoft Works\WksSb.exe
C:\Program Files\ScanSoft\OmniPageSE2.0\OpwareSE2.exe
C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\Java\jre1.5.0_09\bin\jusched.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\WINDOWS\vsnpstd.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Google\GoogleToolbarNotifier\1.2.1128.5462\GoogleToolbarNotifier.exe
C:\Program Files\Internet Explorer\IEXPLORE.EXE
C:\Program Files\Fichiers communs\Microsoft Shared\Works Shared\wkcalrem.exe
C:\Program Files\Internet Explorer\IEXPLORE.EXE
C:\Program Files\Spybot - Search & Destroy\SpybotSD.exe
C:\Documents and Settings\All Users\Documents\Mes téléchargements\HijackThis.exe

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
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll (file missing)
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 5.0\Reader\ActiveX\AcroIEHelper.ocx
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar3.dll
O2 - BHO: Barre d'outils MSN Search Helper - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Toolbar Suite\TB\02.05.0000.1105\fr-fr\msntb.dll
O3 - Toolbar: Easy-WebPrint - {327C2873-E90D-4c37-AA9D-10AC9BABA46C} - C:\Program Files\Canon\Easy-WebPrint\Toolband.dll
O3 - Toolbar: Barre d'outils MSN Search - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Toolbar Suite\TB\02.05.0000.1105\fr-fr\msntb.dll
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\Program Files\Yahoo!\Companion\Installs\cpn\yt.dll (file missing)
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar3.dll
O4 - HKLM\..\Run: [WorksFUD] C:\Program Files\Microsoft Works\wkfud.exe
O4 - HKLM\..\Run: [Microsoft Works Portfolio] C:\Program Files\Microsoft Works\WksSb.exe /AllUsers
O4 - HKLM\..\Run: [Microsoft Works Update Detection] C:\Program Files\Microsoft Works\WkDetect.exe
O4 - HKLM\..\Run: [OpwareSE2] "C:\Program Files\ScanSoft\OmniPageSE2.0\OpwareSE2.exe"
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\System32\NeroCheck.exe
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\WINDOWS\System32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [nwiz] nwiz.exe /install
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.5.0_09\bin\jusched.exe"
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [snpstd] C:\WINDOWS\vsnpstd.exe
O4 - HKLM\..\Run: [AntiRealBoneHeck] C:\Documents and Settings\All Users\Application Data\tons surf anti real\secondinter.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\1.2.1128.5462\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [logo cast] C:\DOCUME~1\Marie\APPLIC~1\DRAWPO~1\shimmags.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office\OSA9.EXE
O4 - Global Startup: Rappels du Calendrier Microsoft Works.lnk = ?
O4 - Global Startup: Windows Desktop Search.lnk = C:\Program Files\MSN Toolbar Suite\DS\02.05.0001.1119\fr-fr\bin\WindowsSearch.exe
O8 - Extra context menu item: &MSN Search - res://C:\Program Files\MSN Toolbar Suite\TB\02.05.0000.1105\fr-fr\msntb.dll/search.htm
O8 - Extra context menu item: Ouvrir dans un nouvel onglet d'arrière-plan - res://C:\Program Files\MSN Toolbar Suite\TAB\02.05.0000.1105\fr-fr\msntabres.dll/229?1a8cfb7b245a4a5d82b71f8b99f78bdb
O8 - Extra context menu item: Ouvrir dans un nouvel onglet de premier plan - res://C:\Program Files\MSN Toolbar Suite\TAB\02.05.0000.1105\fr-fr\msntabres.dll/230?1a8cfb7b245a4a5d82b71f8b99f78bdb
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0_09\bin\ssv.dll
O9 - Extra button: Organise-notes - {9455301C-CF6B-11D3-A266-00C04F689C50} - C:\Program Files\Fichiers communs\Microsoft Shared\Reference 2001\EROProj.dll
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - %windir%\Network Diagnostic\xpnetdiag.exe (file missing)
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
O11 - Options group: [INTERNATIONAL] International*
O16 - DPF: {09CC593B-E8A9-4491-927D-A3E33534DDD4} (InstallerObj Class) - http://mm.tf1.fr/superdistribution/installer2.cab
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) - http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/micros [...] 9835434124
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/micros [...] 9835415858
O16 - DPF: {A1F2F2CE-06AF-483C-9F12-D3BAA72477D6} (BatchDownloader Class) - http://appdirectory.messenger.msn. [...] gWXMSN.cab
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
O20 - Winlogon Notify: WgaLogon - C:\WINDOWS\SYSTEM32\WgaLogon.dll
O21 - SSODL: WPDShServiceObj - {AAA288BA-9A4C-45B0-95D7-94D524869DB5} - C:\WINDOWS\system32\WPDShServiceObj.dll
O23 - Service: AntiVir PersonalEdition Classic Scheduler (AntiVirScheduler) - Avira GmbH - C:\Program Files\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: AntiVir PersonalEdition Classic Guard (AntiVirService) - AVIRA GmbH - C:\Program Files\AntiVir PersonalEdition Classic\avguard.exe
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: iPodService - Apple Computer, Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\System32\nvsvc32.exe

Merci beaucoup d'avance pour l'aide que vous pourrez m'apporter.