Alarme pc? qu'est que ca veut dire?

bonjour,
pardonnez moi si je ne suis pas dans le bon forum, mais je suis un peu perdue, je ne sais pas si j'ai un virus ou pas (mon anti-virus ne me dit rien)
voilà mon souci, cela fait deux fois que mon pc se met à sonner comme une alarme
il n'y a pas de moment particulier
j'ai aussi lu que cela pouvait venir d'une surchauffe, mais quand mon pc s'est mis à sonner c'était peut de temps après l'allumage
il a déjà tourné plus longtemps sans aucun problème
je ne sais pas si vous avez besoin de mon rapport hijackthis mais je vous le donne quand meme au cas ou........

voici le rapport hijackthis :

Logfile of HijackThis v1.99.1
Scan saved at 11:58:58, on 04/04/2007
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v6.00 SP2 (6.00.2900.2180)

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\Ati2evxx.exe
C:\WINDOWS\Explorer.EXE
C:\WINDOWS\system32\spoolsv.exe
C:\WINDOWS\system32\atiptaxx.exe
C:\WINDOWS\soundman.exe
C:\WINDOWS\system32\dla\tfswctrl.exe
C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIABE.EXE
C:\Program Files\Hercules\Hercules DualPix HD Webcam\CamService.exe
C:\Program Files\QuickTime\qttask.exe
C:\Program Files\TechCity Solutions\AliceSAV\AliceAgent.exe
C:\Program Files\Softwin\BitDefender10\bdmcon.exe
C:\Program Files\Softwin\BitDefender10\bdagent.exe
C:\Program Files\Olivetti\ANY_WAY\olDvcStatus.exe
C:\Program Files\ATI Technologies\ATI.ACE\cli.exe
C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe
C:\Program Files\Fichiers communs\InstallShield\UpdateService\issch.exe
C:\Program Files\Java\jre1.5.0\bin\jusched.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Fichiers communs\Ahead\lib\NMBgMonitor.exe
C:\Program Files\SAGEM\SAGEM F@st 800-840\dslmon.exe
C:\Program Files\Fichiers communs\Microsoft Shared\VS7DEBUG\MDM.EXE
C:\Program Files\Olivetti\ANY_WAY\olMntrService.exe
C:\Program Files\Wireless 802.11g Monitor\WLService.exe
C:\Program Files\Wireless 802.11g Monitor\WLanCfgG.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Fichiers communs\Softwin\BitDefender Communicator\xcommsvr.exe
C:\Program Files\Fichiers communs\Softwin\BitDefender Scan Server\bdss.exe
C:\Program Files\Fichiers communs\Softwin\BitDefender Update Service\livesrv.exe
C:\Program Files\Softwin\BitDefender10\vsserv.exe
C:\WINDOWS\system32\wscntfy.exe
C:\Program Files\ATI Technologies\ATI.ACE\cli.exe
C:\Program Files\ATI Technologies\ATI.ACE\cli.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Program Files\Hijackthis Version Française\hijackthis vf.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = https://www.orange.fr/portail
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = https://portail.free.fr/
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Bar = http://fr.rd.yahoo.com/customize/ie/defaults/sb/ymsgr6/fr/*http://www.yahoo.com/ext/search/search.html
R1 - HKCU\Software\Microsoft\Internet Explorer\Search,SearchAssistant = https://portail.free.fr/
R1 - HKCU\Software\Microsoft\Internet Explorer\SearchURL,(Default) = http://fr.rd.yahoo.com/customize/ie/defaults/su/ymsgr6/fr/*https://fr.yahoo.com/
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Alice ADSL
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHlprObj Class - {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: (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
O2 - BHO: EpsonToolBandKicker Class - {E99421FB-68DD-40F0-B4AC-B7027CAE2F1A} - C:\Program Files\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O3 - Toolbar: EPSON Web-To-Page - {EE5D279F-081B-4404-994D-C6B60AAEBA6D} - C:\Program Files\EPSON\EPSON Web-To-Page\EPSON Web-To-Page.dll
O4 - HKLM\..\Run: [ATIPTA] atiptaxx.exe
O4 - HKLM\..\Run: [SoundMan] soundman.exe
O4 - HKLM\..\Run: [dla] C:\WINDOWS\system32\dla\tfswctrl.exe
O4 - HKLM\..\Run: [EPSON Stylus D88 Series] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIABE.EXE /P23 "EPSON Stylus D88 Series" /O6 "USB001" /M "Stylus D88"
O4 - HKLM\..\Run: [NeroFilterCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [EPSON Stylus D88 Series (Copie 1)] C:\WINDOWS\System32\spool\DRIVERS\W32X86\3\E_FATIABE.EXE /P33 "EPSON Stylus D88 Series (Copie 1)" /O5 "LPT1:" /M "Stylus D88"
O4 - HKLM\..\Run: [HerculesCamService] C:\Program Files\Hercules\Hercules DualPix HD Webcam\CamService.exe
O4 - HKLM\..\Run: [QuickTime Task] "C:\Program Files\QuickTime\qttask.exe" -atboottime
O4 - HKLM\..\Run: [AliceSAV] C:\Program Files\TechCity Solutions\AliceSAV\AliceAgent.exe
O4 - HKLM\..\Run: [BDMCon] "C:\Program Files\Softwin\BitDefender10\bdmcon.exe" /reg
O4 - HKLM\..\Run: [BDAgent] "C:\Program Files\Softwin\BitDefender10\bdagent.exe"
O4 - HKLM\..\Run: [OlStatusMon] "C:\Program Files\Olivetti\ANY_WAY\olDvcStatus.exe" dvcStatusMinimize
O4 - HKLM\..\Run: [ATICCC] "C:\Program Files\ATI Technologies\ATI.ACE\cli.exe" runtime -Delay
O4 - HKLM\..\Run: [!AVG Anti-Spyware] "C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\avgas.exe" /minimized
O4 - HKLM\..\Run: [UnlockerAssistant] "C:\Program Files\Unlocker\UnlockerAssistant.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: [SunJavaUpdateSched] C:\Program Files\Java\jre1.5.0\bin\jusched.exe
O4 - HKCU\..\Run: [ctfmon.exe] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [BgMonitor_{79662E04-7C6C-4d9f-84C7-88D8A56B10AA}] "C:\Program Files\Fichiers communs\Ahead\lib\NMBgMonitor.exe"
O4 - Startup: Adobe Gamma.lnk = C:\Program Files\Fichiers communs\Adobe\Calibration\Adobe Gamma Loader.exe
O4 - Global Startup: DSLMON.lnk = C:\Program Files\SAGEM\SAGEM F@st 800-840\dslmon.exe
O4 - Global Startup: Lancement rapide d'Adobe Reader.lnk = C:\Program Files\Adobe\Acrobat 7.0\Reader\reader_sl.exe
O8 - Extra context menu item: E&xporter vers Microsoft Excel - res://C:\PROGRA~1\MICROS~2\OFFICE11\EXCEL.EXE/3000
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0\bin\npjpi150.dll
O9 - Extra 'Tools' menuitem: Console Java (Sun) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Program Files\Java\jre1.5.0\bin\npjpi150.dll
O9 - Extra button: (no name) - {85d1f590-48f4-11d9-9669-0800200c9a66} - %windir%\bdoscandel.exe (file missing)
O9 - Extra 'Tools' menuitem: Uninstall BitDefender Online Scanner v8 - {85d1f590-48f4-11d9-9669-0800200c9a66} - %windir%\bdoscandel.exe (file missing)
O9 - Extra button: Recherche - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~2\OFFICE11\REFIEBAR.DLL
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)
O12 - Plugin for .spop: C:\Program Files\Internet Explorer\Plugins\NPDocBox.dll
O16 - DPF: {5D86DDB5-BDF9-441B-9E9E-D4730F4EE499} (BDSCANONLINE Control) - http://download.bitdefender.com/resources/scan8/oscan8.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{B0D00B4F-5086-4F69-83B8-106E7F9222F2}: NameServer = 192.168.1.1
O18 - Protocol: livecall - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
O18 - Protocol: msnim - {828030A1-22C1-4009-854F-8E305202313F} - C:\PROGRA~1\MSNMES~1\MSGRAP~1.DLL
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: BitDefender Scan Server (bdss) - Unknown owner - C:\Program Files\Fichiers communs\Softwin\BitDefender Scan Server\bdss.exe" /service (file missing)
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Program Files\Fichiers communs\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: BitDefender Desktop Update Service (LIVESRV) - Unknown owner - C:\Program Files\Fichiers communs\Softwin\BitDefender Update Service\livesrv.exe" /service (file missing)
O23 - Service: olMntrService - Olivetti - C:\Program Files\Olivetti\ANY_WAY\olMntrService.exe
O23 - Service: R54G Wireless Service - Unknown owner - C:\Program Files\Wireless 802.11g Monitor\WLService.exe
O23 - Service: BitDefender Virus Shield (VSSERV) - Unknown owner - C:\Program Files\Softwin\BitDefender10\vsserv.exe" /service (file missing)
O23 - Service: BitDefender Communicator (XCOMM) - Unknown owner - C:\Program Files\Fichiers communs\Softwin\BitDefender Communicator\xcommsvr.exe" /service (file missing)

merci de m'avoir lu et j'attend vos directives