Lag important

Defragmente, et arrette de téléchrger (et d'installer !) n'importe quoi.
Ca devrai déja aider.
Puis, installe HiJackThis et vois un peu si utu peux enlever des trucs.
A mon avis, tu as trop de processus (de programmes) en même temps.

Ceci dit, à ce stade, le plus efficace reste de reformater et de ne plus installer n'importe quoi à l'avenir. =)

d'accord, je te remercie, sinon avec hijack, comment savoir ce que je dois enlever?

Ce logiciel ne permet que de retirer des programmes/services ou autre se lancan au démarrage.
Mais il ne t'informe pas duquel supprimer et duquel ne pas supprimmer.
https://www.bleepingcomputer.com/tutorials/comment-utiliser-hijackthis/
Donc, en théorie, tu ne dois laisser que els lignes correspondant aux logiciels que tu souhaite voir se lancer.
EN pratique, certains parraissent en trop, mais sont indispensable au lancement de windows, attention...

voila ce qu'il m'affiche:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 23:08:28, on 08/01/2008
Platform: Windows Vista (WinNT 6.00.1904)
MSIE: Internet Explorer v7.00 (7.00.6000.16575)
Boot mode: Normal

Running processes:
C:\Windows\system32\Dwm.exe
C:\Windows\system32\taskeng.exe
C:\Windows\Explorer.EXE
C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
C:\Program Files\HP\QuickPlay\QPService.exe
C:\Program Files\HP\HP Software Update\hpwuSchd2.exe
C:\Windows\System32\rundll32.exe
C:\Program Files\Java\jre1.6.0\bin\jusched.exe
C:\Program Files\Alwil Software\Avast4\ashDisp.exe
C:\Windows\ehome\ehtray.exe
C:\Users\antoine\Program Files\BitTorrent_DNA\dna.exe
C:\Program Files\Windows Media Player\wmpnscfg.exe
C:\Windows\ehome\ehmsas.exe
C:\Windows\system32\conime.exe
C:\Windows\system32\conime.exe
C:\Windows\system32\conime.exe
C:\Windows\system32\conime.exe
C:\Windows\System32\mobsync.exe
C:\Program Files\BitTorrent\bittorrent.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\Windows\system32\SearchFilterHost.exe
C:\Program Files\Trend Micro\HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = https://www.bing.com/?toHttps=1&redig=5FC791212101479BAFBE1A679848B1AF
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://ie.redirect.hp.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 = http://ie.redirect.hp.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 =
O1 - Hosts: ::1 localhost
O2 - BHO: Aide pour le lien d'Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: Media Holding Enterprises, LLC - {0D39A900-0F3A-4C29-A254-3E65244FDC34} - (no file)
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Program Files\Java\jre1.6.0\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar2.dll
O2 - BHO: (no name) - {C7C90A5E-BE0A-44DD-83D2-1BE138460BAC} - (no file)
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar2.dll
O4 - HKLM\..\Run: [NvSvc] RUNDLL32.EXE C:\Windows\system32\nvsvc.dll,nvsvcStart
O4 - HKLM\..\Run: [NvCplDaemon] RUNDLL32.EXE C:\Windows\system32\NvCpl.dll,NvStartup
O4 - HKLM\..\Run: [NvMediaCenter] RUNDLL32.EXE C:\Windows\system32\NvMcTray.dll,NvTaskbarInit
O4 - HKLM\..\Run: [SynTPEnh] C:\Program Files\Synaptics\SynTP\SynTPEnh.exe
O4 - HKLM\..\Run: [QPService] "C:\Program Files\HP\QuickPlay\QPService.exe"
O4 - HKLM\..\Run: [HP Software Update] C:\Program Files\Hp\HP Software Update\HPWuSchd2.exe
O4 - HKLM\..\Run: [HP Health Check Scheduler] C:\Program Files\Hewlett-Packard\HP Health Check\HPHC_Scheduler.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0\bin\jusched.exe"
O4 - HKLM\..\Run: [MSConfig] "C:\Windows\system32\msconfig.exe" /auto
O4 - HKLM\..\Run: [nod32kui] "C:\Program Files\Eset\nod32kui.exe" /WAITSERVICE
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [a-squared] "C:\Program Files\a-squared Anti-Malware\a2guard.exe"
O4 - HKLM\..\RunOnce: [Launcher] %WINDIR%\SMINST\launcher.exe
O4 - HKCU\..\Run: [ehTray.exe] C:\Windows\ehome\ehTray.exe
O4 - HKCU\..\Run: [SpybotSD TeaTimer] C:\Program Files\Spybot - Search & Destroy\TeaTimer.exe
O4 - HKCU\..\Run: [BitTorrent DNA] "C:\Users\antoine\Program Files\BitTorrent_DNA\dna.exe"
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - HKCU\..\Run: [msnmsgr] "C:\Program Files\MSN Messenger\msnmsgr.exe" /background
O4 - HKCU\..\Run: [LanceurEasyBox] "C:\Program Files\EasyBox\EasyBox.exe" -AutoStart
O4 - HKUS\S-1-5-19\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-19\..\Run: [WindowsWelcomeCenter] rundll32.exe oobefldr.dll,ShowWelcomeCenter (User 'SERVICE LOCAL')
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /detectMem (User 'SERVICE RÉSEAU')
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0\bin\ssv.dll
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\OFFICE11\REFIEBAR.DLL
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search & Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\PROGRA~1\SPYBOT~1\SDHelper.dll
O13 - Gopher Prefix:
O23 - Service: a-squared Anti-Malware Service (a2AntiMalware) - Emsi Software GmbH - C:\Program Files\a-squared Anti-Malware\a2service.exe
O23 - Service: a-squared Free Service (a2free) - Emsi Software GmbH - C:\Program Files\a-squared Free\a2service.exe
O23 - Service: AddFiltr - Hewlett-Packard Development Company, L.P. - C:\Program Files\Hewlett-Packard\HP Quick Launch Buttons\AddFiltr.exe
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Program Files\Alwil Software\Avast4\aswUpdSv.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: CyberLink Background Capture Service (CBCS) (CLCapSvc) - Unknown owner - C:\Program Files\HP\QuickPlay\Kernel\TV\CLCapSvc.exe
O23 - Service: CyberLink Task Scheduler (CTS) (CLSched) - Unknown owner - C:\Program Files\HP\QuickPlay\Kernel\TV\CLSched.exe
O23 - Service: Symantec Lic NetConnect service (CLTNetCnService) - Unknown owner - c:\Program Files\Common Files\Symantec Shared\ccSvcHst.exe (file missing)
O23 - Service: Google Updater Service (gusvc) - Google - C:\Program Files\Google\Common\Google Updater\GoogleUpdaterService.exe
O23 - Service: HP Health Check Service - Hewlett-Packard - C:\Program Files\Hewlett-Packard\HP Health Check\hphc_service.exe
O23 - Service: hpqwmiex - Hewlett-Packard Development Company, L.P. - C:\Program Files\Hewlett-Packard\Shared\hpqwmiex.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Common Files\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: iPod Service - Apple Computer, 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: NOD32 Kernel Service (NOD32krn) - Eset - C:\Program Files\Eset\nod32krn.exe
O23 - Service: PnkBstrA - Unknown owner - C:\Windows\system32\PnkBstrA.exe
O23 - Service: RoxMediaDB9 - Sonic Solutions - C:\Program Files\Common Files\Roxio Shared\9.0\SharedCOM\RoxMediaDB9.exe
O23 - Service: SBSD Security Center Service (SBSDWSCService) - Safer Networking Ltd. - C:\Program Files\Spybot - Search & Destroy\SDWinSec.exe
O23 - Service: Steam Client Service - Valve Corporation - C:\Program Files\Common Files\Steam\SteamService.exe
O23 - Service: stllssvr - MicroVision Development, Inc. - C:\Program Files\Common Files\SureThing Shared\stllssvr.exe
O23 - Service: XAudioService - Conexant Systems, Inc. - C:\Windows\system32\DRIVERS\xaudio.exe

Je suis pas spécialiste de l'analyse des rapports HJT.
Ceci dit, je pense qu'il y a qqes lignes supprimmables, mais riend e bien méchant.

Ceci dit², il y a des gens ici qui sauraient te dire