A l'aide svp!!! gros probleme de virus

Bonjour,
voila mon soucis je vien d'acheter un pc d'occasion et le probleme c'est qu'il rame a mort et je ne souhaite pas le formater aidez moi svp merci d'avance je vous joint un rapport hijackthis Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 18:30:18, on 28/01/2009
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16762)
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\spoolsv.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\sched.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avguard.exe
C:\WINDOWS\system32\PSIService.exe
C:\Program Files\Microsoft\Search Enhancement Pack\SeaPort\SeaPort.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\SOUNDMAN.EXE
C:\WINDOWS\system32\VTTimer.exe
C:\WINDOWS\system32\VTtrayp.exe
C:\WINDOWS\FixCamera.exe
C:\WINDOWS\tsnpstd3.exe
C:\WINDOWS\vsnpstd3.exe
C:\WINDOWS\system32\rundll32.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\Windows Live\Messenger\msnmsgr.exe
C:\Program Files\Windows Live\Contacts\wlcomm.exe
C:\WINDOWS\System32\svchost.exe
C:\Documents and Settings\famille\Application Data\Microsoft\Live Search\Notification-LiveSearch.exe
C:\Documents and Settings\famille\Application Data\Microsoft\Live Search\Mise-a-jour-LiveSearch.exe
C:\Program Files\Fichiers communs\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\QuickTime\QTTask.exe
C:\Program Files\Bonjour\mDNSResponder.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\iTunes\iTunes.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
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://home.sweetim.com
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = *.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
R3 - URLSearchHook: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: Search Helper - {6EBF7485-159F-4bff-A14F-B9E3AAC4465B} - C:\Program Files\Microsoft\Search Enhancement Pack\Search Helper\SearchHelper.dll
O2 - BHO: Programme d'aide de l'Assistant de connexion Windows Live - {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\googletoolbar1.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 - {E15A8DC0-8516-42A1-81EA-DC94EC1ACF10} - C:\Program Files\Windows Live\Toolbar\wltcore.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll
O3 - Toolbar: &Windows Live Toolbar - {21FA44EF-376D-4D53-9B0F-8A89D3229068} - C:\Program Files\Windows Live\Toolbar\wltcore.dll
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [VTTimer] VTTimer.exe
O4 - HKLM\..\Run: [VTTrayp] VTtrayp.exe
O4 - HKLM\..\Run: [FixCamera] C:\WINDOWS\FixCamera.exe
O4 - HKLM\..\Run: [tsnpstd3] C:\WINDOWS\tsnpstd3.exe
O4 - HKLM\..\Run: [snpstd3] C:\WINDOWS\vsnpstd3.exe
O4 - HKLM\..\Run: [CloneCDTray] "C:\Program Files\SlySoft\CloneCD\CloneCDTray.exe" /s
O4 - HKLM\..\Run: [BluetoothAuthenticationAgent] rundll32.exe bthprops.cpl,,BluetoothAuthenticationAgent
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\QTTask.exe" -atboottime
O4 - HKLM\..\Run: [iTunesHelper] "C:\Program Files\iTunes\iTunesHelper.exe"
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
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\S-1-5-18\..\RunOnce: [WUAppSetup] C:\Program Files\Fichiers communs\logishrd\WUApp32.exe -v 0x046d -p 0x092e -f video -m logitech -d 10.5.1.2023 (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O4 - HKUS\.DEFAULT\..\RunOnce: [WUAppSetup] C:\Program Files\Fichiers communs\logishrd\WUApp32.exe -v 0x046d -p 0x092e -f video -m logitech -d 10.5.1.2023 (User 'Default user')
O4 - S-1-5-18 Startup: Outil de notification Live Search.lnk = C:\Documents and Settings\famille\Application Data\Microsoft\Live Search\Notification-LiveSearch.exe (User 'SYSTEM')
O4 - .DEFAULT Startup: Outil de notification Live Search.lnk = C:\Documents and Settings\famille\Application Data\Microsoft\Live Search\Notification-LiveSearch.exe (User 'Default user')
O4 - Startup: Outil de notification Live Search.lnk = C:\Documents and Settings\famille\Application Data\Microsoft\Live Search\Notification-LiveSearch.exe
O4 - Global Startup: Adobe Reader Speed Launch.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~3\Office12\EXCEL.EXE/3000
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: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\Office12\REFIEBAR.DLL
O9 - Extra button: (no name) - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
O9 - Extra 'Tools' menuitem: @xpsp3res.dll,-20001 - {e2e2dd38-d088-4134-82b7-f2ba38496583} - C:\WINDOWS\Network Diagnostic\xpnetdiag.exe
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
O9 - Extra button: Allocam Multi Vision - {2D6B57BF-71FA-41A3-BDC5-3B5A25813D2E} - C:\WINDOWS\system32\shdocvw.dll (HKCU)
O9 - Extra 'Tools' menuitem: Allocam Multi Vision - {2D6B57BF-71FA-41A3-BDC5-3B5A25813D2E} - C:\WINDOWS\system32\shdocvw.dll (HKCU)
O16 - DPF: {029FDBA6-3547-11D7-AA4C-0050BF051A00} (Rawflow ICD Client) - http://s.tf1.fr/mmdia/static/rawflow/clients/5.3.1.0/Rawflow.cab
O16 - DPF: {20A60F0D-9AFA-4515-A0FD-83BD84642501} (Checkers Class) - http://messenger.zone.msn.com/binary/msgrchkr.cab56986.cab
O16 - DPF: {30528230-99f7-4bb4-88d8-fa1d4f56a2ab} (YInstStarter Class) - C:\Program Files\Yahoo!\Common\yinsthelper.dll
O16 - DPF: {4F1E5B1A-2A80-42CA-8532-2D05CB959537} (MSN Photo Upload Tool) - http://gfx1.hotmail.com/mail/w2/pr02/resources/MSNPUpld.cab
O16 - DPF: {5D6F45B3-9043-443D-A792-115447494D24} (UnoCtrl Class) - http://messenger.zone.msn.com/FR-FR/a-UNO1/GAME_UNO1.cab
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://www.bitdefender.fr/scan_fr/scan8/oscan8.cab
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsClient.cab31267.cab
O16 - DPF: {BD8667B7-38D8-4C77-B580-18C3E146372C} (Creative Toolbox Plug-in) - http://bmm.imgag.com/imgag/cp/install/crusher-fr.cab
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O16 - DPF: {D8089245-3211-40F6-819B-9E5E92CD61A2} (FlashXControl Object) - https://register3.valueactive.com/323/webolr/OCX/FlashAX.cab
O16 - DPF: {F5A7706B-B9C0-4C89-A715-7A0C6B05DD48} (Minesweeper Flags Class) - http://messenger.zone.msn.com/binary/MineSweeper.cab56986.cab
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Fichiers communs\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: Planificateur Avira AntiVir Personal - Free Antivirus (AntiVirScheduler) - Avira GmbH - C:\Program Files\Avira\AntiVir PersonalEdition Classic\sched.exe
O23 - Service: Avira AntiVir Personal - Free Antivirus Guard (AntiVirService) - Avira GmbH - C:\Program Files\Avira\AntiVir PersonalEdition Classic\avguard.exe
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Fichiers communs\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: Service Bonjour (Bonjour Service) - Apple Inc. - C:\Program Files\Bonjour\mDNSResponder.exe
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Service de l’iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: Logitech Process Monitor (LVPrcSrv) - Unknown owner - (no file)
O23 - Service: LVSrvLauncher - Logitech Inc. - C:\Program Files\Fichiers communs\LogiShrd\SrvLnch\SrvLnch.exe
O23 - Service: ProtexisLicensing - Unknown owner - C:\WINDOWS\system32\PSIService.exe
O23 - Service: Windows Live Setup Service (WLSetupSvc) - Unknown owner - C:\Program Files\Windows Live\installer\WLSetupSvc.exe