PC lent au démarrage et sur Internet - Virus?

Bonjour,

mon pc est très lent au démarrage de Windows 7 et lorsque je lance Internet, j'arrive à afficher iGoogle qu'au bout de 20min. J'ai passé Avast et Spybot dessus mais rien n'y fait, j'ai toujours le soucis. J'ai donc fait un HijackThis pour faire appel aux experts qui gère ce domaine. Voici donc mon rapport :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 20:40:58, on 20/09/2010
Platform: Unknown Windows (WinNT 6.01.3504)
MSIE: Internet Explorer v8.00 (8.00.7600.16385)
Boot mode: Normal

Running processes:
C:\windows\system32\Dwm.exe
C:\windows\Explorer.EXE
C:\windows\system32\taskhost.exe
C:\Program Files\Realtek\Audio\HDA\RtHDVCpl.exe
C:\windows\system32\taskeng.exe
C:\Program Files\Samsung\Samsung Recovery Solution 4\WCScheduler.exe
C:\Program Files\Samsung\Samsung Support Center\SSCKbdHk.exe
C:\Program Files\SAMSUNG\EasySpeedUpManager\EasySpeedUpManager.exe
C:\Program Files\Samsung\Easy Display Manager\dmhkcore.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\Synaptics\SynTP\SynTPHelper.exe
C:\Program Files\Alwil Software\Avast5\AvastUI.exe
C:\Program Files\WIDCOMM\Bluetooth Software\BTTray.exe
C:\Program Files\WIDCOMM\Bluetooth Software\BtStackServer.exe
C:\windows\system32\SearchFilterHost.exe
C:\Users\Sophie\Desktop\HiJackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
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 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
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: SkypeIEPluginBHO - {AE805869-2E5C-4ED4-8F7B-F1F7851A4497} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\windows\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [RtHDVCpl] C:\Program Files\Realtek\Audio\HDA\RtHDVCpl.exe -s
O4 - HKLM\..\Run: [SynTPEnh] %ProgramFiles%\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [UCam_Menu] "C:\Program Files\CyberLink\YouCam\MUITransfer\MUIStartMenu.exe" "C:\Program Files\CyberLink\YouCam" UpdateWithCreateOnce "Software\CyberLink\YouCam\2.0"
O4 - HKLM\..\Run: [AdobeCS4ServiceManager] "C:\Program Files\Common Files\Adobe\CS4ServiceManager\CS4ServiceManager.exe" -launchedbylogin
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 9.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [Adobe ARM] "C:\Program Files\Common Files\Adobe\ARM\1.0\AdobeARM.exe"
O4 - HKLM\..\Run: [avast5] "C:\Program Files\Alwil Software\Avast5\avastUI.exe" /nogui
O4 - HKCU\..\Run: [Google Update] "C:\Users\Sophie\AppData\Local\Google\Update\GoogleUpdate.exe" /c
O4 - HKCU\..\Run: [DAEMON Tools Lite] "C:\Program Files\DAEMON Tools Lite\DTLite.exe" -autorun
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-19\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User 'SERVICE RÉSEAU')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User 'SERVICE RÉSEAU')
O4 - Global Startup: Bluetooth.lnk = ?
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
O8 - Extra context menu item: Envoyer au périphérique &Bluetooth... - C:\Program Files\WIDCOMM\Bluetooth Software\btsendto_ie.htm
O8 - Extra context menu item: Envoyer l'&image au périphérique Bluetooth... - C:\Program Files\WIDCOMM\Bluetooth Software\btsendto_ie_ctx.htm
O8 - Extra context menu item: Google Sidewiki... - res://C:\Program Files\Google\Google Toolbar\Component\GoogleToolbarDynamic_mui_en_96D6FF0C6D236BF8.dll/cmsidewiki.html
O9 - Extra button: Skype add-on for Internet Explorer - {898EA8C8-E7FF-479B-8935-AEC46303B9E5} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O9 - Extra 'Tools' menuitem: Skype add-on for Internet Explorer - {898EA8C8-E7FF-479B-8935-AEC46303B9E5} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O9 - Extra button: @C:\Program Files\WIDCOMM\Bluetooth Software\btrez.dll,-4015 - {CCA281CA-C863-46ef-9331-5C8D4460577F} - C:\Program Files\WIDCOMM\Bluetooth Software\btsendto_ie.htm
O9 - Extra 'Tools' menuitem: @C:\Program Files\WIDCOMM\Bluetooth Software\btrez.dll,-12650 - {CCA281CA-C863-46ef-9331-5C8D4460577F} - C:\Program Files\WIDCOMM\Bluetooth Software\btsendto_ie.htm
O13 - Gopher Prefix:
O16 - DPF: {E2883E8F-472F-4FB0-9522-AC9BF37916A7} - http://platformdl.adobe.com/NOS/getPlusPlus/1.6/gp.cab
O18 - Protocol: skype-ie-addon-data - {91774881-D725-4E58-B298-07617B9B86A8} - C:\Program Files\Skype\Toolbars\Internet Explorer\skypeieplugin.dll
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\COMMON~1\Skype\SKYPE4~1.DLL
O23 - Service: avast! Antivirus - AVAST Software - C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
O23 - Service: avast! Mail Scanner - AVAST Software - C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
O23 - Service: avast! Web Scanner - AVAST Software - C:\Program Files\Alwil Software\Avast5\AvastSvc.exe
O23 - Service: Bluetooth Service (btwdins) - Broadcom Corporation. - C:\Program Files\WIDCOMM\Bluetooth Software\btwdins.exe
O23 - Service: FLEXnet Licensing Service - Acresso Software Inc. - C:\Program Files\Common Files\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: Service Google Update (gupdate) (gupdate) - Google Inc. - C:\Program Files\Google\Update\GoogleUpdate.exe
O23 - Service: NVIDIA Display Driver Service (nvsvc) - NVIDIA Corporation - C:\windows\system32\nvvsvc.exe
O23 - Service: Rezip - Unknown owner - C:\windows\SYSTEM32\Rezip.exe