Virus ou pas ? Rapport HiJackThis

Bonjour,
J'ai mon ordinateur qui rame de plus en plus et j'aimerais savoir si j'ai un virus !

Voici le rapport HiJackThis :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16:48:49, on 24/07/2009
Platform: Windows Vista (WinNT 6.00.1904)
MSIE: Internet Explorer v7.00 (7.00.6000.16851)
Boot mode: Normal

Running processes:
C:\Windows\system32\Dwm.exe
C:\Windows\Explorer.EXE
C:\Windows\system32\taskeng.exe
C:\Program Files\Alwil Software\Avast4\ashDisp.exe
C:\Program Files\Google\Quick Search Box\GoogleQuickSearchBox.exe
C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Windows\System32\mobsync.exe
C:\Windows\system32\wuauclt.exe
C:\Program Files\Steam\Steam.exe
C:\Program Files\Windows Media Player\wmplayer.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Users\Jojo\Desktop\HiJackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://fr.rd.yahoo.com/customize/ycomp/defaults/sp/*https://fr.yahoo.com/
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://www.google.fr/?gws_rd=ssl
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://fr.fr.acer.yahoo.com
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 = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = https://fr.yahoo.com/
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: Yahoo! Toolbar avec bloqueur de fenêtres pop-up - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - (no file)
O1 - Hosts: ::1 localhost
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: (no name) - {83A2F9B1-01A2-4AA5-87D1-45B6B8505E96} - (no file)
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - C:\Program Files\Google\Google Toolbar\GoogleToolbar_32.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\5.2.4204.1700\swg.dll
O2 - BHO: Google Dictionary Compression sdch - {C84D72FE-E17D-4195-BB24-76C02E2E7C4E} - C:\Program Files\Google\Google Toolbar\Component\fastsearch_B7C5AC242193BB3E.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: Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files\Google\Google Toolbar\GoogleToolbar_32.dll
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [Google Quick Search Box] "C:\Program Files\Google\Quick Search Box\GoogleQuickSearchBox.exe" /autorun
O4 - HKLM\..\Run: [ZoneAlarm Client] "C:\Program Files\Zone Labs\ZoneAlarm\zlclient.exe"
O4 - HKCU\..\Run: [MsnMsgr] "C:\Program Files\MSN Messenger\MsnMsgr.Exe" /background
O4 - HKCU\..\Run: [Steam] "c:\program files\steam\steam.exe" -silent
O4 - HKCU\..\Run: [swg] "C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe"
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - HKUS\S-1-5-18\..\Run: [] (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\Run: [StartCCC] C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\CLIStart.exe (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\Run: [Acer Tour Reminder] C:\Acer\AcerTour\Reminder.exe (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [] (User 'Default user')
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office12\EXCEL.EXE/3000
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\Office12\REFIEBAR.DLL
O13 - Gopher Prefix:
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\COMMON~1\Skype\SKYPE4~1.DLL
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Program Files\Common Files\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: Ati External Event Utility - ATI Technologies Inc. - C:\Windows\system32\Ati2evxx.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: eRecovery Service (eRecoveryService) - Acer Inc. - C:\Acer\Empowering Technology\eRecovery\eRecoveryService.exe
O23 - Service: FLEXnet Licensing Service - Macrovision Europe Ltd. - C:\Program Files\Common Files\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: Google Software Updater (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: LightScribeService Direct Disc Labeling Service (LightScribeService) - Hewlett-Packard Company - C:\Program Files\Common Files\LightScribe\LSSrvc.exe
O23 - Service: MSSQL$SONY_MEDIAMGR - Unknown owner - C:\Program Files\Sony\Shared Plug-Ins\Media Manager\MSSQL$SONY_MEDIAMGR\Binn\sqlservr.exe (file missing)
O23 - Service: SQLAgent$SONY_MEDIAMGR - Unknown owner - C:\Program Files\Sony\Shared Plug-Ins\Media Manager\MSSQL$SONY_MEDIAMGR\Binn\sqlagent.EXE (file missing)
O23 - Service: Steam Client Service - Valve Corporation - C:\Program Files\Common Files\Steam\SteamService.exe
O23 - Service: TrueVector Internet Monitor (vsmon) - Check Point Software Technologies LTD - C:\Windows\System32\ZoneLabs\vsmon.exe