Ordinateur très lent...

Bonjour, j'envoie un rapport hijackthis pour comprendre la lenteur d'un pc que je viens de récupérer. Il en est à planter pendant l'analyse virus d'avast!
D'avance merci pour votre aide qui me sera, j'en suis sûr, précieuse.

Rapport:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 22:25:44, on 20/03/2012
Platform: Windows Vista SP2 (WinNT 6.00.1906)
MSIE: Internet Explorer v8.00 (8.00.6001.19120)
Boot mode: Normal

Running processes:
C:\Windows\system32\taskeng.exe
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\Realtek Semiconductor Corp\Realtek Card Reader Monitor\CardReaderMonitor.exe
C:\Program Files\Common Files\Roxio Shared\9.0\SharedCOM\RoxWatchTray9.exe
C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
C:\Program Files\Common Files\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\PIFSvc.exe
C:\Program Files\Orange\Systray\SystrayApp.exe
C:\Windows\WindowsMobile\wmdSync.exe
C:\Windows\System32\rundll32.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Common Files\Java\Java Update\jusched.exe
C:\Program Files\AVAST Software\Avast\AvastUI.exe
C:\Windows\ehome\ehtray.exe
C:\Program Files\RocketDock\RocketDock.exe
C:\Program Files\Microsoft Office\Office12\ONENOTEM.EXE
C:\Program Files\Microsoft Works\WkCalRem.exe
C:\Windows\System32\rundll32.exe
C:\Windows\ehome\ehmsas.exe
C:\PROGRA~1\COMMON~1\France Telecom\Shared Modules\AlertModule\0\AlertModule.exe
C:\Program Files\Common Files\Roxio Shared\9.0\SharedCOM\CPSHelpRunner.exe
C:\Windows\system32\wuauclt.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Windows\system32\conime.exe
C:\Users\martin\Downloads\hijackthis_telechargement_01net.exe
C:\Windows\system32\Macromed\Flash\FlashUtil9d.exe
C:\Windows\system32\SearchFilterHost.exe
C:\Users\martin\AppData\Local\Temp\01net\HiJackThis.exe
C:\Windows\system32\DllHost.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://format.packardbell.com/cgi-bin/redirect/?country=FR&range=AD&phase=8&key=IESTART
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.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
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
R3 - URLSearchHook: Search Class - {08C06D61-F1F3-4799-86F8-BE1A89362C85} - C:\Program Files\Orange\SearchURLHook\SearchPageURL.dll
R3 - URLSearchHook: Audacity-tools Toolbar - {d0b1518e-3e45-4d16-a23b-4d90ef938e44} - C:\Program Files\Audacity-tools\tbAuda.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: Winamp Toolbar Loader - {25CEE8EC-5730-41bc-8B58-22DDC8AB8C20} - C:\Program Files\Winamp Toolbar\winamptb.dll
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre6\bin\ssv.dll
O2 - BHO: avast! WebRep - {8E5E2654-AD2D-48bf-AC2D-D17F00898D06} - C:\Program Files\AVAST Software\Avast\aswWebRepIE.dll
O2 - BHO: CBrowserHelperObject Object - {CA6319C0-31B7-401E-A518-A07C3DB8F777} - C:\Program Files\Google\Google_BAE\BAE.dll
O2 - BHO: Audacity-tools Toolbar - {d0b1518e-3e45-4d16-a23b-4d90ef938e44} - C:\Program Files\Audacity-tools\tbAuda.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: Audacity-tools Toolbar - {d0b1518e-3e45-4d16-a23b-4d90ef938e44} - C:\Program Files\Audacity-tools\tbAuda.dll
O3 - Toolbar: avast! WebRep - {8E5E2654-AD2D-48bf-AC2D-D17F00898D06} - C:\Program Files\AVAST Software\Avast\aswWebRepIE.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: [CardReaderMonitor] C:\Program Files\Realtek Semiconductor Corp.\Realtek Card Reader Monitor\CardReaderMonitor.exe
O4 - HKLM\..\Run: [RoxWatchTray] "C:\Program Files\Common Files\Roxio Shared\9.0\SharedCOM\RoxWatchTray9.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: [Symantec PIF AlertEng] "C:\Program Files\Common Files\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\PIFSvc.exe" /a /m "C:\Program Files\Common Files\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\AlertEng.dll"
O4 - HKLM\..\Run: [ORAHSSSessionManager] C:\Program Files\Orange\SessionManager\SessionManager.exe
O4 - HKLM\..\Run: [SystrayORAHSS] "C:\Program Files\Orange\Systray\SystrayApp.exe"
O4 - HKLM\..\Run: [Windows Mobile-based device management] %windir%\WindowsMobile\wmdSync.exe
O4 - HKLM\..\Run: [Adobe Reader Speed Launcher] "C:\Program Files\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [NvSvc] RUNDLL32.EXE C:\Windows\system32\nvsvc.dll,nvsvcStart
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: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Common Files\Java\Java Update\jusched.exe"
O4 - HKLM\..\Run: [avast] "C:\Program Files\AVAST Software\Avast\avastUI.exe" /nogui
O4 - HKCU\..\Run: [ehTray.exe] C:\Windows\ehome\ehTray.exe
O4 - HKCU\..\Run: [RocketDock] "C:\Program Files\RocketDock\RocketDock.exe"
O4 - HKCU\..\Run: [Google Update] "C:\Users\martin\AppData\Local\Google\Update\GoogleUpdate.exe" /c
O4 - HKCU\..\Run: [ccleaner] "C:\Program Files\CCleaner\CCleaner.exe" /AUTO
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 - Startup: OneNote 2007 - Capture d'écran et lancement.lnk = C:\Program Files\Microsoft Office\Office12\ONENOTEM.EXE
O4 - Startup: wkcalrem.LNK = C:\Program Files\Microsoft Works\WkCalRem.exe
O8 - Extra context menu item: &Winamp Search - C:\ProgramData\Winamp Toolbar\ieToolbar\resources\en-US\local\search.html
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~3\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Envoyer à OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: &Envoyer à OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra button: PokerStars.fr - {90EAE591-7E7E-434a-8E28-ECFD00071806} - C:\Program Files\PokerStars.FR\PokerStarsUpdate.exe (file missing)
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\OFFICE11\REFIEBAR.DLL
O13 - Gopher Prefix:
O20 - AppInit_DLLs: C:\PROGRA~1\Google\GOOGLE~3\GOEC62~1.DLL
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\AppleMobileDeviceService.exe
O23 - Service: avast! Antivirus - AVAST Software - C:\Program Files\AVAST Software\Avast\AvastSvc.exe
O23 - Service: Service Bonjour (Bonjour Service) - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: Symantec Lic NetConnect service (CLTNetCnService) - Unknown owner - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe (file missing)
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 5.9.1005.12335 (GoogleDesktopManager-051210-111108) - Google - C:\Program Files\Google\Google Desktop Search\GoogleDesktop.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\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: LiveUpdate - Symantec Corporation - C:\PROGRA~1\Symantec\LIVEUP~1\LUCOMS~1.EXE
O23 - Service: LiveUpdate Notice Service Ex (LiveUpdate Notice Ex) - Unknown owner - C:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe (file missing)
O23 - Service: LiveUpdate Notice Service - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\PIF\{B8E1DD85-8582-4c61-B58F-2F227FCA9A08}\PIFSvc.exe
O23 - Service: RoxMediaDB9 - Sonic Solutions - C:\Program Files\Common Files\Roxio Shared\9.0\SharedCOM\RoxMediaDB9.exe
O23 - Service: Roxio Hard Drive Watcher 9 (RoxWatch9) - Sonic Solutions - C:\Program Files\Common Files\Roxio Shared\9.0\SharedCOM\RoxWatch9.exe
O23 - Service: stllssvr - MicroVision Development, Inc. - C:\Program Files\Common Files\SureThing Shared\stllssvr.exe