Pub intempestives et lenteur de l'ordi

Bonjour,
Alors voila mon problème, depuis quelques jours, mon ordi et bien plus lent que d'habitude et j'ai des pages de pub qui s'affiche en permanence lorsque je suis sur internet.

J'ai télécharger hijackthis et voici mon raport :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 14:19:52, on 13/10/2008
Platform: Windows Vista SP1 (WinNT 6.00.1905)
MSIE: Internet Explorer v7.00 (7.00.6001.18000)
Boot mode: Normal

Running processes:
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Program Files\Windows Defender\MSASCui.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Common Files\aol\1171291994\ee\aolsoftware.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\Orange\Systray\SystrayApp.exe
C:\Program Files\Common Files\Real\Update_OB\realsched.exe
C:\Windows\System32\hkcmd.exe
C:\Windows\System32\igfxpers.exe
C:\Program Files\Alwil Software\Avast4\ashDisp.exe
C:\Windows\system32\taskeng.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Windows Sidebar\sidebar.exe
C:\Program Files\Packard Bell\SetUpMyPC\SmpSys.exe
C:\Windows\ehome\ehtray.exe
C:\Program Files\Windows Live\Messenger\msnmsgr.exe
C:\Users\Melanie Ricouard\AppData\Local\giscawk.exe
C:\Windows\system32\igfxsrvc.exe
C:\Program Files\Orange\Launcher\Launcher.exe
C:\Windows\ehome\ehmsas.exe
C:\PROGRA~1\COMMON~1\France Telecom\Shared Modules\AlertModule\0\AlertModule.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\Orange\Deskboard\deskboard.exe
C:\Program Files\Orange\connectivity\connectivitymanager.exe
C:\Program Files\Orange\connectivity\CoreCom\CoreCom.exe
C:\Program Files\Orange\connectivity\CoreCom\OraConfigRecover.exe
C:\PROGRA~1\COMMON~1\France Telecom\Shared Modules\FTCOMModule\0\FTCOMModule.exe
C:\Windows\system32\SearchFilterHost.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe
C:\Windows\system32\DllHost.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.msn.com/fr-fr/?ocid=iehp
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: Search Class - {08C06D61-F1F3-4799-86F8-BE1A89362C85} - C:\Program Files\Orange\SearchURLHook\SearchPageURL.dll
O1 - Hosts: ::1 localhost
O2 - BHO: Aide pour le lien d'Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: RealPlayer Download and Record Plugin for Internet Explorer - {3049C3E9-B461-4BC5-8870-4C09146192CA} - C:\Program Files\Real\RealPlayer\rpbrowserrecordplugin.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: Browser Address Error Redirector - {CA6319C0-31B7-401E-A518-A07C3DB8F777} - C:\Program Files\Google\Google_BAE\BAE.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [Windows Defender] %ProgramFiles%\Windows Defender\MSASCui.exe -hide
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [HostManager] C:\Program Files\Common Files\AOL\1171291994\ee\AOLSoftware.exe
O4 - HKLM\..\Run: [Google Desktop Search] "C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe" /startup
O4 - HKLM\..\Run: [toolbar_eula_launcher] C:\Program Files\Packard Bell\GOOGLE_EULA\EULALauncher.exe
O4 - HKLM\..\Run: [SystrayORAHSS] "C:\Program Files\Orange\Systray\SystrayApp.exe"
O4 - HKLM\..\Run: [ORAHSSSessionManager] C:\Program Files\Orange\SessionManager\SessionManager.exe
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Common Files\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [IgfxTray] C:\Windows\system32\igfxtray.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\Windows\system32\hkcmd.exe
O4 - HKLM\..\Run: [Persistence] C:\Windows\system32\igfxpers.exe
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [AppleSyncNotifier] C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleSyncNotifier.exe
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\RunOnce: [AOLRebootNeeded] regsvr32.exe /s
O4 - HKCU\..\Run: [Sidebar] C:\Program Files\Windows Sidebar\sidebar.exe /autoRun
O4 - HKCU\..\Run: [WindowsWelcomeCenter] rundll32.exe oobefldr.dll,ShowWelcomeCenter
O4 - HKCU\..\Run: [SmpcSys] C:\Program Files\Packard Bell\SetUpMyPC\SmpSys.exe
O4 - HKCU\..\Run: [ehTray.exe] C:\Windows\ehome\ehTray.exe
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\Windows Live\Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [messengerskinner] C:\Program Files\MessengerSkinner\MessengerSkinner.exe
O4 - HKCU\..\Run: [giscawk] "c:\users\melanie ricouard\appdata\local\giscawk.exe" giscawk
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-19\..\Run: [WindowsWelcomeCenter] rundll32.exe oobefldr.dll,ShowWelcomeCenter (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'SERVICE RÉSEAU')
O4 - Global Startup: OFFICE One Startup v7.lnk = ?
O13 - Gopher Prefix:
O15 - Trusted Zone: https://www.orange.fr/portail
O20 - AppInit_DLLs: C:\PROGRA~1\Google\GOOGLE~2\GOEC62~1.DLL
O23 - Service: Lavasoft Ad-Aware Service (aawservice) - Lavasoft - C:\Program Files\Lavasoft\Ad-Aware\aawservice.exe
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: ASLDR Service (ASLDRService) - Unknown owner - C:\Program Files\ATK Hotkey\ASLDRSrv.exe
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - ALWIL Software - 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: Service Bonjour (Bonjour Service) - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: France Telecom Routing Table Service (FTRTSVC) - France Telecom SA - C:\PROGRA~1\COMMON~1\France Telecom\Shared Modules\FTRTSVC\0\FTRTSVC.exe
O23 - Service: Google Desktop Manager 5.7.806.10245 (GoogleDesktopManager-061008-081103) - Google - C:\Program Files\Google\Google Desktop Search\GoogleDesktop.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\Common Files\InstallShield\Driver\1150\Intel 32\IDriverT.exe
O23 - Service: Service de l'iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Planificateur LiveUpdate automatique - Unknown owner - C:\Program Files\Symantec\LiveUpdate\ALUSchedulerSvc.exe (file missing)
O23 - Service: Syntek AVStream USB2.0 WebCam Service (StkSSrv) - Syntek America Inc. - C:\Windows\System32\StkSrv.exe
O23 - Service: Symantec Core LC - Unknown owner - C:\Program Files\Common Files\Symantec Shared\CCPD-LC\symlcsvc.exe