Présence de virus ?

Bonjour,
Suis actuellement en grande difficulté face cet ordinateur dont les subtilités de fonctionnement échappent complètement à mon grand âge.
Une âme charitable accepterait -elle de me venir en aide?
Qu'elle en soit par avance remerciée!
Bien cordialement
(ci-joint détail de mon installation

Logfile of HijackThis v1.99.1
Scan saved at 22:10:12, on 05/06/2005
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\svchost.exe
C:\WINDOWS\System32\svchost.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
C:\Program Files\Alwil Software\Avast4\ashServ.exe
C:\PROGRA~1\F-Secure\BackWeb\7681197\Program\SERVIC~1.EXE
C:\Program Files\F-Secure\Anti-Virus\fsgk32st.exe
C:\Program Files\F-Secure\Anti-Virus\FSGK32.EXE
C:\Program Files\F-Secure\BackWeb\7681197\program\fsbwsys.exe
C:\Program Files\F-Secure\Common\FSMA32.EXE
C:\Program Files\F-Secure\Anti-Virus\fssm32.exe
C:\Program Files\F-Secure\Common\FSMB32.EXE
C:\Program Files\F-Secure\Common\FCH32.EXE
C:\Program Files\F-Secure\Common\FAMEH32.EXE
C:\WINDOWS\Explorer.EXE
C:\Program Files\F-Secure\Common\FNRB32.EXE
C:\Program Files\F-Secure\Common\FIH32.EXE
C:\Program Files\F-Secure\Anti-Virus\fsav32.exe
C:\Program Files\F-Secure\FWES\Program\fsdfwd.exe
C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe
C:\Program Files\Alwil Software\Avast4\ashWebSv.exe
C:\Program Files\F-Secure\Common\FSM32.EXE
C:\WINDOWS\SOUNDMAN.EXE
C:\Program Files\Fichiers communs\Microsoft Shared\Works Shared\WkUFind.exe
C:\Program Files\USB Media\shwicon.exe
C:\WINDOWS\tppaldr.exe
C:\Program Files\MSN Apps\Updater\01.02.3000.1001\fr\msnappau.exe
C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\WINDOWS\system32\ctfmon.exe
C:\Program Files\Messenger\msmsgs.exe
C:\Program Files\NETGEAR\WG121 Configuration Utility\wlancfg8.exe
C:\Palm\HOTSYNC.EXE
C:\WINDOWS\System32\svchost.exe
C:\Program Files\F-Secure\BackWeb\7681197\Program\BackWeb-7681197.exe
C:\WINDOWS\System32\svchost.exe
C:\Program Files\Internet Explorer\iexplore.exe
C:\Documents and Settings\JeanPhi.JUILLOT-H69J30X\Bureau\hijackthis_199\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Connection Wizard,ShellNext = http://home.free.fr/
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = localhost
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Liens
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Program Files\Adobe\Acrobat 6.0\Reader\ActiveX\AcroIEHelper.dll
O2 - BHO: ST - {9394EDE7-C8B5-483E-8773-474BF36AF6E4} - C:\Program Files\MSN Apps\ST\01.03.0000.1005\en-xu\stmain.dll
O2 - BHO: Google Toolbar Helper - {AA58ED58-01DD-4d91-8333-CF10577473F7} - c:\program files\google\googletoolbar1.dll
O2 - BHO: MSNToolBandBHO - {BDBD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.4000.1001\fr\msntb.dll
O3 - Toolbar: MSN - {BDAD1DAD-C946-4A17-ADC1-64B5B4FF55D0} - C:\Program Files\MSN Apps\MSN Toolbar\01.02.4000.1001\fr\msntb.dll
O3 - Toolbar: &Google - {2318C2B1-4965-11d4-9B18-009027A5CD4F} - c:\program files\google\googletoolbar1.dll
O4 - HKLM\..\Run: [F-Secure Manager] "C:\Program Files\F-Secure\Common\FSM32.EXE" /splash
O4 - HKLM\..\Run: [F-Secure TNB] "C:\Program Files\F-Secure\TNB\TNBUtil.exe" /CHECKALL
O4 - HKLM\..\Run: [SoundMan] SOUNDMAN.EXE
O4 - HKLM\..\Run: [Microsoft Works Update Detection] C:\Program Files\Fichiers communs\Microsoft Shared\Works Shared\WkUFind.exe
O4 - HKLM\..\Run: [ShowIcon_Vosonic_USB Media Device Driver v1.19r003] "C:\Program Files\USB Media\shwicon.exe" -t"Vosonic\USB Media Device Driver v1.19r003"
O4 - HKLM\..\Run: [TPP Auto Loader] C:\WINDOWS\tppaldr.exe
O4 - HKLM\..\Run: [NeroCheck] C:\WINDOWS\system32\NeroCheck.exe
O4 - HKLM\..\Run: [msnappau] "C:\Program Files\MSN Apps\Updater\01.02.3000.1001\fr\msnappau.exe"
O4 - HKLM\..\Run: [TkBellExe] "C:\Program Files\Fichiers communs\Real\Update_OB\realsched.exe" -osboot
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [MSMSGS] "C:\Program Files\Messenger\msmsgs.exe" /background
O4 - HKCU\..\Run: [a-squared] "C:\Program Files\a2\a2guard.exe"
O4 - Startup: HotSync Manager.lnk = C:\Palm\HOTSYNC.EXE
O4 - Global Startup: Microsoft Office.lnk = C:\Program Files\Microsoft Office\Office\OSA9.EXE
O4 - Global Startup: Smart Wizard Wireless Settings.lnk = ?
O4 - Global Startup: Adobe Gamma Loader.lnk = C:\Program Files\Fichiers communs\Adobe\Calibration\Adobe Gamma Loader.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: {084DAC27-6FA3-4F55-9005-033F2F102F5C} (ITPPDiagIE Class) - http://downloads.winwise.fr/Common/npwwg.cab
O16 - DPF: {380C4261-4FC3-40D0-ADF8-0240A5857CE6} (Aurigma Image Uploader 2.5) - http://www.photoweb.fr/france/telechargement-photoweb.cab
O16 - DPF: {68C1822F-F5C7-4404-A73F-03C10E0E94DA} (telechargement-photoweb) - http://www2.photoweb.fr/direct/Photoweb_uploader.cab
O16 - DPF: {74D05D43-3236-11D4-BDCD-00C04F9A3B61} (HouseCall Control) - http://a840.g.akamai.net/7/840/537/2004061001/housecall.trendmicro.com/housecall/xscan53.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{A7FABAD8-100C-4767-A8D1-8A662A41D58A}: NameServer = 192.168.123.254
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - Unknown owner - C:\Program Files\Alwil Software\Avast4\aswUpdSv.exe
O23 - Service: avast! Antivirus - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashMaiSv.exe" /service (file missing)
O23 - Service: avast! Web Scanner - Unknown owner - C:\Program Files\Alwil Software\Avast4\ashWebSv.exe" /service (file missing)
O23 - Service: F-Secure Automatic Update (BackWeb Client - 7681197) - Unknown owner - C:\PROGRA~1\F-Secure\BackWeb\7681197\Program\SERVIC~1.EXE
O23 - Service: F-Secure Gatekeeper Handler Starter - F-Secure Corp. - C:\Program Files\F-Secure\Anti-Virus\fsgk32st.exe
O23 - Service: F-Secure Network Request Broker - F-Secure Corporation - C:\Program Files\F-Secure\Common\FNRB32.EXE
O23 - Service: fsbwsys - F-Secure Corp. - C:\Program Files\F-Secure\BackWeb\7681197\program\fsbwsys.exe
O23 - Service: F-Secure Anti-Virus Firewall Daemon (FSDFWD) - F-Secure Corporation - C:\Program Files\F-Secure\FWES\Program\fsdfwd.exe
O23 - Service: F-Secure Management Agent (FSMA) - F-Secure Corporation - C:\Program Files\F-Secure\Common\FSMA32.EXE