Ordinateur super lent de temps en temps

Bonjour,

Ca se passe mon ordinateur du boulot, 512 Mb de RAM seulement.

Il est parfois hyper-lent (quasi à l'arrêt) alors que le "commit charge" de la mémoire n'est pas énorme.
Pour le moment ça va très bien... (sinon je ne sais même plus arriver sur un forum)

J'ai déjà
-Lancé un cleanup spybot
-CCleaner (registry)
-supprimé quelques services/autorun inutiles avec Hijackthis

Le log actuel d'HijackThis :

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 14:15:08, on 23/04/2009
Platform: Windows XP SP3 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16827)
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:\WINDOWS\system32\cisvc.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Java\jre6\bin\jqs.exe
C:\Program Files\Network Associates\Common Framework\FrameworkService.exe
C:\Program Files\McAfee\VirusScan Enterprise\Mcshield.exe
C:\Program Files\McAfee\VirusScan Enterprise\VsTskMgr.exe
C:\Program Files\Common Files\Microsoft Shared\VS7DEBUG\MDM.EXE
c:\Program Files\Microsoft SQL Server\90\Shared\sqlwriter.exe
C:\Program Files\Sun\jstudio_ent81\collab\bin\xmppd-jse.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\Network Associates\Common Framework\UdaterUI.exe
C:\WINDOWS\system32\hkcmd.exe
C:\WINDOWS\system32\igfxpers.exe
C:\WINDOWS\RTHDCPL.EXE
C:\Program Files\McAfee\VirusScan Enterprise\SHSTAT.EXE
C:\Program Files\Network Associates\Common Framework\McTray.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
C:\WINDOWS\system32\cidaemon.exe
C:\WINDOWS\system32\cidaemon.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\WINDOWS\system32\taskmgr.exe
C:\Program Files\Q-Dir\Q-Dir.exe
C:\Program Files\Hijackthis\HijackThis.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://intranet/default.aspx
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = https://www.msn.com/fr-fr/?ocid=iehp
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
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://www.msn.com/fr-fr/?ocid=iehp
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: RealPlayer Download and Record Plugin for Internet Explorer - {3049C3E9-B461-4BC5-8870-4C09146192CA} - C:\Program Files\Real\RealPlayer\rpbrowserrecordplugin.dll
O2 - BHO: scriptproxy - {7DB2D5A0-7241-4E79-B68D-6309F01C5231} - C:\Program Files\McAfee\VirusScan Enterprise\scriptcl.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\5.1.1309.3572\swg.dll
O2 - BHO: Google Dictionary Compression sdch - {C84D72FE-E17D-4195-BB24-76C02E2E7C4E} - C:\Program Files\Google\Google Toolbar\Component\fastsearch_219B3E1547538286.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
O3 - Toolbar: Copernic Desktop Search 2 - {968631B6-4729-440D-9BF4-251F5593EC9A} - C:\Program Files\Copernic Desktop Search 2\DesktopSearchBand2526.dll
O3 - Toolbar: &Google Toolbar - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - C:\Program Files\Google\Google Toolbar\GoogleToolbar.dll
O4 - HKLM\..\Run: [McAfeeUpdaterUI] "C:\Program Files\Network Associates\Common Framework\UdaterUI.exe" /StartedFromRunKey
O4 - HKLM\..\Run: [igfxhkcmd] C:\WINDOWS\system32\hkcmd.exe
O4 - HKLM\..\Run: [igfxpers] C:\WINDOWS\system32\igfxpers.exe
O4 - HKLM\..\Run: [RTHDCPL] RTHDCPL.EXE
O4 - HKLM\..\Run: [ShStatEXE] "C:\Program Files\McAfee\VirusScan Enterprise\SHSTAT.EXE" /STANDALONE
O4 - HKLM\..\Run: [MSPY2002] C:\WINDOWS\system32\IME\PINTLGNT\ImScInst.exe /SYNC
O4 - HKLM\..\Run: [Synchronization Manager] %SystemRoot%\system32\mobsync.exe /logon
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [swg] C:\Program Files\Google\GoogleToolbarNotifier\GoogleToolbarNotifier.exe
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\Run: [DWQueuedReporting] "C:\PROGRA~1\COMMON~1\MICROS~1\DW\dwtrig20.exe" -t (User 'SYSTEM')
O4 - HKUS\S-1-5-18\..\RunOnce: [TSClientMSIUninstaller] cmd.exe /C "cscript %systemroot%\Installer\TSClientMsiTrans\tscuinst.vbs" (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O4 - HKUS\.DEFAULT\..\RunOnce: [TSClientMSIUninstaller] cmd.exe /C "cscript %systemroot%\Installer\TSClientMsiTrans\tscuinst.vbs" (User 'Default user')
O8 - Extra context menu item: E&xport to Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: Create Mobile Favorite - {2EAF5BB1-070F-11D3-9307-00C04FAE2D4F} - C:\PROGRA~1\MI3AA1~1\INetRepl.dll
O9 - Extra button: (no name) - {2EAF5BB2-070F-11D3-9307-00C04FAE2D4F} - C:\PROGRA~1\MI3AA1~1\INetRepl.dll
O9 - Extra 'Tools' menuitem: Create Mobile Favorite... - {2EAF5BB2-070F-11D3-9307-00C04FAE2D4F} - C:\PROGRA~1\MI3AA1~1\INetRepl.dll
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\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
O16 - DPF: {05CA9FB0-3E3E-4B36-BF41-0E3A5CAA8CD8} (Office Genuine Advantage Validation Tool) - http://download.microsoft.com/download/C/B/F/CBF23A2C-3E55-4664-BC5C-762780D79BA0/OGAControl.cab
O16 - DPF: {0E8D0700-75DF-11D3-8B4A-0008C7450C4A} (DjVuCtl Class) - http://www.lizardtech.com/download/files/win/djvuplugin/fr_FR/DjVuControl_fr_FR.cab
O16 - DPF: {6E32070A-766D-4EE6-879C-DC1FA91D2FC3} (MUWebControl Class) - http://update.microsoft.com/...
O16 - DPF: {82774781-8F4E-11D1-AB1C-0000F8773BF0} (DLC Class) - https://transfers.ds.microsoft.com/FTM/TransferSource/grTransferCtrl.cab
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Common Files\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: Google Software Updater (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: Java Quick Starter (JavaQuickStarterService) - Sun Microsystems, Inc. - C:\Program Files\Java\jre6\bin\jqs.exe
O23 - Service: McAfee Framework Service (McAfeeFramework) - McAfee, Inc. - C:\Program Files\Network Associates\Common Framework\FrameworkService.exe
O23 - Service: McAfee McShield (McShield) - McAfee, Inc. - C:\Program Files\McAfee\VirusScan Enterprise\Mcshield.exe
O23 - Service: McAfee Task Manager (McTaskManager) - McAfee, Inc. - C:\Program Files\McAfee\VirusScan Enterprise\VsTskMgr.exe
O23 - Service: Collaboration Runtime Service (xmppd-jse) - Unknown owner - C:\Program Files\Sun\jstudio_ent81\collab\bin\xmppd-jse.exe