PC très très lent = virus??

merci pour ton aide!
voici le rapport :




Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 11:50:09, on 2/05/2009
Platform: Windows XP SP1 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)
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:\Program Files\Java\jre6\bin\jqs.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\System32\WgaTray.exe
C:\Program Files\MSN Messenger\usnsvc.exe
C:\WINDOWS\System32\LVComsX.exe
C:\Program Files\MSN Messenger\msnmsgr.exe
C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe
C:\WINDOWS\System32\wuauclt.exe
C:\Program Files\trend micro\HijackThis\HijackThis.exe

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://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 = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
O2 - BHO: Java(tm) Plug-In SSV Helper - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre6\bin\ssv.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files\Java\jre6\bin\jp2ssv.dll
O2 - BHO: JQSIEStartDetectorImpl - {E7E6F031-17CE-4C07-BC86-EABFE594F69C} - C:\Program Files\Java\jre6\lib\deploy\jqs\ie\jqs_plugin.dll
O4 - HKLM\..\Run: [avgnt] "C:\Program Files\Avira\AntiVir PersonalEdition Classic\avgnt.exe" /min
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'Default user')
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\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
O10 - Unknown file in Winsock LSP: c:\windows\system32\nwprovau.dll
O14 - IERESET.INF: START_PAGE_URL=http://www.google.fr
O16 - DPF: {4F1E5B1A-2A80-42CA-8532-2D05CB959537} (MSN Photo Upload Tool) - http://gfx1.hotmail.com/mail/w3/resources/MSNPUpld.cab
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://www.bitdefender.fr/scan_fr/scan8/oscan8.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://www.update.microsoft.com/...
O16 - DPF: {8AD9C840-044E-11D1-B3E9-00805F499D93} (Java Runtime Environment 1.6.0) - https://sdlc-esd.oracle.com/ESD5/JSCDL/jre/6u11-b90/jinstall-6u11-windows-i586-jc.cab?GroupName=JSC&FilePath=/ESD5/JSCDL/jre/6u11-b90/jinstall-6u11-windows-i586-jc.cab&BHost=javadl.sun.com&File=jinstall-6u11-windows-i586-jc.cab&AuthParam=1580990370_ae51af1f2e3e7c78a0fbe2e88da6073d&ext=.cab
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: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: Java Quick Starter (JavaQuickStarterService) - Sun Microsystems, Inc. - C:\Program Files\Java\jre6\bin\jqs.exe

Comment ça piraté? J'ai windows xp sp1.