Voilà:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16:48:00, on 20/09/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16512)
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\Ati2evxx.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe

C:\PROGRA~1\Belkin\BELKIN~1\Tool\WinXPDisableZeroC
onfigation.exe
C:\Program Files\Java\jre1.6.0_01\bin\jusched.exe
C:\WINDOWS\ALCWZRD.EXE
C:\Program Files\Fichiers communs\InstallShield\UpdateService\issch.exe
C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\MOM.EXE
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Windows Media Player\WMPNSCFG.exe
C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\ccc.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\System32\WLTRYSVC.EXE
C:\WINDOWS\System32\bcmwltry.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\Mozilla Firefox\firefox.exe
C:\WINDOWS\system32\msiexec.exe
C:\Program Files\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page =
http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page =
http://www.jeuvideo.com/
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 =
http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page =
http://go.microsoft.com/fwlink/?LinkId=69157
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: HelperObject Class - {00C6482D-C502-44C8-8409-FCE54AD9C208} - C:\Program Files\TechSmith\SnagIt 8\SnagItBHO.dll
O2 - BHO: Adobe PDF Reader Link Helper - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 7.0\ActiveX\AcroIEHelper.dll
O2 - BHO: (no name) - {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_02\bin\ssv.dll
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files\Fichiers communs\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O3 - Toolbar: SnagIt - {8FF5E183-ABDE-46EB-B09E-D2AAB95CABE3} - C:\Program Files\TechSmith\SnagIt 8\SnagItIEAddin.dll
O4 - HKLM\..\Run: [Raccourci vers la page des propriétés de High Definition Audio] HDAudPropShortcut.exe
O4 - HKLM\..\Run: [ATIPTA] "C:\Program Files\ATI Technologies\ATI Control Panel\atiptaxx.exe"
O4 - HKLM\..\Run: [XpDis0Conf]
C:\PROGRA~1\Belkin\BELKIN~1\Tool\WinXPDisableZeroC
onfigation.exe VEN_14E4&DEV_4320&SUBSYS_70011799 /d
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Program Files\Java\jre1.6.0_01\bin\jusched.exe"
O4 - HKLM\..\Run: [zBrowser Launcher] C:\Program Files\Logitech\iTouch\iTouch.exe
O4 - HKLM\..\Run: [kav] "C:\Program Files\Kaspersky Lab\Kaspersky Anti-Virus 6.0\avp.exe"
O4 - HKLM\..\Run: [High Definition Audio Property Page Shortcut] HDAShCut.exe
O4 - HKLM\..\Run: [AlcWzrd] ALCWZRD.EXE
O4 - HKLM\..\Run: [Alcmtr] ALCMTR.EXE
O4 - HKLM\..\Run: [StartCCC] C:\Program Files\ATI Technologies\ATI.ACE\Core-Static\CLIStart.exe
O4 - HKLM\..\Run: [ISUSPM Startup] C:\PROGRA~1\FICHIE~1\INSTAL~1\UPDATE~1\isuspm.exe -startup
O4 - HKLM\..\Run: [ISUSScheduler] "C:\Program Files\Fichiers communs\InstallShield\UpdateService\issch.exe" -start
O4 - HKLM\..\Run: [Adobe Photo Downloader] "C:\Program Files\Adobe\Photoshop Album Starter Edition\3.0\Apps\apdproxy.exe"
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [WMPNSCFG] C:\Program Files\Windows Media Player\WMPNSCFG.exe
O4 - Startup: Registration .LNK = C:\Program Files\Valve\Steam\SteamApps\yvanlfdth\Dark Messiah of Might and Magic\Dark Messiah of Might and Magic\RegistrationReminder.exe
O8 - Extra context menu item: &Search -
http://bar.mywebsearch.com/menusearch.html?p=ZNxdm414YYBE
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra ´Tools´ menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra button: Antivirus Internet - {1F460357-8A94-4D71-9CA3-AA4ACF32ED8E} - C:\Program Files\Kaspersky Lab\Kaspersky Anti-Virus 6.0\scieplugin.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 (file missing)
O9 - Extra ´Tools´ menuitem: Windows Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Program Files\Messenger\msmsgs.exe (file missing)
O10 - Unknown file in Winsock LSP: c:\windows\system32\nwprovau.dll
O14 - IERESET.INF: START_PAGE_URL=
http://www.skynet.be
O16 - DPF: {00B71CFB-6864-4346-A978-C0A14556272C} (Checkers Class) -
http://messenger.zone.msn.com/binary/msgrchkr.cab31267.cab
O16 - DPF: {14B87622-7E19-4EA8-93B3-97215F77A6BC} (MessengerStatsClient Class) -
http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab31267.cab
O16 - DPF: {17492023-C23A-453E-A040-C7C580BBF700} (Windows Genuine Advantage Validation Tool) -
http://go.microsoft.com/fwlink/?linkid=39204
O16 - DPF: {2917297F-F02B-4B9D-81DF-494B6333150B} (Minesweeper Flags Class) -
http://messenger.zone.msn.com/binary/MineSweeper.cab31267.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) -
http://v5.windowsupdate.microsoft.com/v5consumer/V5Controls/en/x86/client/wuweb_site.cab?1103546850734
O16 - DPF: {8E0D4DE5-3180-4024-A327-4DFAD1796A8D} (MessengerStatsClient Class) -
http://messenger.zone.msn.com/binary/MessengerStatsClient.cab31267.cab
O16 - DPF: {B8BE5E93-A60C-4D26-A2DC-220313175592} (ZoneIntro Class) -
http://messenger.zone.msn.com/binary/ZIntro.cab32846.cab
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) -
http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O17 -
HKLM\System\CCS\Services\Tcpip\..\{79741310-EEC8-4
B33-BA4D-BE76B82AE8C7}: NameServer = 195.238.2.21,195.238.2.22
O23 - Service: Adobe LM Service - Adobe Systems - C:\Program Files\Fichiers communs\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: Ati HotKey Poller - ATI Technologies Inc. - C:\WINDOWS\system32\Ati2evxx.exe
O23 - Service: ATI Smart - Unknown owner - C:\WINDOWS\system32\ati2sgag.exe
O23 - Service: AVG Anti-Spyware Guard - Anti-Malware Development a.s. - C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\guard.exe
O23 - Service: Kaspersky Anti-Virus 6.0 (AVP) - Kaspersky Lab - C:\Program Files\Kaspersky Lab\Kaspersky Anti-Virus 6.0\avp.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\1150\Intel 32\IDriverT.exe
O23 - Service: iPodService - Unknown owner - C:\Program Files\iPod\bin\iPodService.exe (file missing)
O23 - Service: PnkBstrA - Unknown owner - C:\WINDOWS\system32\PnkBstrA.exe
O23 - Service: PnkBstrB - Unknown owner - C:\WINDOWS\system32\PnkBstrB.exe
O23 - Service: SF FrontLine Drivers Auto Removal (v1) (sfrem01) - Protection Technology (StarForce) - C:\WINDOWS\system32\sfrem01.exe
O23 - Service: WLTRYSVC - Unknown owner - C:\WINDOWS\System32\WLTRYSVC.EXE

--
End of file - 8163 bytes

coches les lignes suivantes puis fix checked

O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)

O4 - HKLM\..\Run: [Alcmtr] ALCMTR.EXE

O8 - Extra context menu item: &Search
-http://bar.mywebsearch.co[...]html?p=ZNxdm414YYBE

voilà, tu n´as pas d´infection
pense à suprimer le fichier ALCMTR.EXE

sinon pour l´utilisation de l´uc quel processus utilise le plus (je parle bien de l´uc donc processeur)

Pour l´uc, il y a WinXPDisableZeroConfigation.exe, Explorer et Processus inactif du système qui bouffent quasi tout.

Ps: Merci de ton aide