Pc lent + antivir perime Centre secu windows

Bonjour,
voici mon souci, depuis qques jours mon pc me parait plutot lent, aussi apres la reinstallation de avira antivir celui ci n'arrive pas à se mettre à jour et le centre de securite windows affiche qu'il est périmé. Pourtant antivir affiche bien "guard actif". je me demande s'il n'y a pas un foutu virus dans mon pc, je poste un hijackthis et si une bonne ame pouvait me venir en aide ce serait tres appreciable ! merci d'avance
ps : je precise que j'utilise firefox comme navigateur...

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 23:26:54, on 10/11/2009
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)
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 Desktop\sched.exe
C:\Program Files\Avira\AntiVir Desktop\avguard.exe
C:\Program Files\Fichiers communs\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\Bonjour\mDNSResponder.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\PC Tools Firewall Plus\FWService.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Microsoft\Search Enhancement Pack\SeaPort\SeaPort.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\WINDOWS\System32\igfxtray.exe
C:\WINDOWS\System32\hkcmd.exe
C:\Program Files\HPQ\Quick Launch Buttons\EabServr.exe
C:\Program Files\Java\j2re1.4.2_05\bin\jusched.exe
C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
C:\Program Files\My Lockbox\flockbox.exe
C:\Program Files\PC Tools Firewall Plus\FirewallGUI.exe
C:\Program Files\QuickTime\QTTask.exe
C:\Program Files\iTunes\iTunesHelper.exe
C:\Program Files\Avira\AntiVir Desktop\avgnt.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\iPod\bin\iPodService.exe
C:\Program Files\HP\Digital Imaging\bin\hpqSTE08.exe
C:\WINDOWS\system32\wuauclt.exe
c:\program files\avira\antivir desktop\avcenter.exe
C:\Program Files\CCleaner\ccleaner.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

O2 - BHO: HP Print Enhancer - {0347C33E-8762-4905-BF09-768834316C61} - C:\Program Files\HP\Smart Web Printing\hpswp_printenhancer.dll
O2 - BHO: HP Print Clips - {053F9267-DC04-4294-A72C-58F732D338C0} - C:\Program Files\HP\Smart Web Printing\hpswp_framework.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\Google Toolbar\GoogleToolbar.dll
O2 - BHO: Google Toolbar Notifier BHO - {AF69DE43-7D58-4638-B6FA-CE66B5AD205D} - C:\Program Files\Google\GoogleToolbarNotifier\5.1.1309.15642\swg.dll
O2 - BHO: Google Dictionary Compression sdch - {C84D72FE-E17D-4195-BB24-76C02E2E7C4E} - C:\Program Files\Google\Google Toolbar\Component\fastsearch_219B3E1547538286.dll
O3 - Toolbar: &Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files\Google\Google Toolbar\GoogleToolbar.dll
O4 - HKLM\..\Run: [SynTPLpr] C:\Program Files\Synaptics\SynTP\SynTPLpr.exe
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [IgfxTray] C:\WINDOWS\System32\igfxtray.exe
O4 - HKLM\..\Run: [HotKeysCmds] C:\WINDOWS\System32\hkcmd.exe
O4 - HKLM\..\Run: [Cpqset] C:\Program Files\HPQ\Default Settings\cpqset.exe
O4 - HKLM\..\Run: [eabconfg.cpl] C:\Program Files\HPQ\Quick Launch Buttons\EabServr.exe /Start
O4 - HKLM\..\Run: [UpdateManager] "C:\Program Files\Fichiers communs\Sonic\Update Manager\sgtray.exe" /r
O4 - HKLM\..\Run: [SunJavaUpdateSched] C:\Program Files\Java\j2re1.4.2_05\bin\jusched.exe
O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\HP\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [flockbox] C:\Program Files\My Lockbox\flockbox.exe /a
O4 - HKLM\..\Run: [00PCTFW] "C:\Program Files\PC Tools Firewall Plus\FirewallGUI.exe" -s
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: [avgnt] "C:\Program Files\Avira\AntiVir Desktop\avgnt.exe" /min
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.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\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\System32\CTFMON.EXE (User 'Default user')
O4 - Global Startup: HP Digital Imaging Monitor.lnk = C:\Program Files\HP\Digital Imaging\bin\hpqtra08.exe
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office10\OSA.EXE
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\Office10\EXCEL.EXE/3000
O9 - Extra button: PokerStars - {3AD14F0C-ED16-4e43-B6D8-661B03F6A1EF} - C:\Program Files\PokerStars\PokerStarsUpdate.exe
O9 - Extra button: Livre de reliures HP - {58ECB495-38F0-49cb-A538-10282ABF65E7} - C:\Program Files\HP\Smart Web Printing\hpswp_extensions.dll
O9 - Extra button: Sélection intelligente HP - {700259D7-1666-479a-93B1-3250410481E8} - C:\Program Files\HP\Smart Web Printing\hpswp_extensions.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
O16 - DPF: {00B71CFB-6864-4346-A978-C0A14556272C} (Checkers Class) - http://messenger.zone.msn.com/binary/msgrchkr.cab31267.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://www.update.microsoft.com/...
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsClient.cab31267.cab
O23 - Service: Avira AntiVir Planificateur (AntiVirSchedulerService) - Avira GmbH - C:\Program Files\Avira\AntiVir Desktop\sched.exe
O23 - Service: Avira AntiVir Guard (AntiVirService) - Avira GmbH - C:\Program Files\Avira\AntiVir Desktop\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: HP WMI Interface (hpqwmi) - Hewlett-Packard Development Company, L.P. - C:\Program Files\HPQ\SHARED\HPQWMI.exe
O23 - Service: Service de l’iPod (iPod Service) - Apple Inc. - C:\Program Files\iPod\bin\iPodService.exe
O23 - Service: PC Tools Firewall Plus (PCToolsFirewallPlus) - PC Tools - C:\Program Files\PC Tools Firewall Plus\FWService.exe