Ecco il log di hijackthis:

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 11.58.34, on 23/10/2009
Platform: Windows XP SP2 (WinNT 5.01.2600)
MSIE: Internet Explorer v7.00 (7.00.6000.16544)
Boot mode: Normal

Running processes:
C:\WINDOWS\System32\smss.exe
C:\WINDOWS\system32\csrss.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\svchost.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\Alwil Software\Avast4\aswUpdSv.exe
C:\WINDOWS\system32\Ati2evxx.exe
C:\Programmi\Alwil Software\Avast4\ashServ.exe
C:\WINDOWS\system32\spoolsv.exe
C:\Programmi\File comuni\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
C:\Program Files\Intel\IDU\awServ.exe
C:\WINDOWS\Explorer.EXE
C:\Programmi\FuzLez\WheelsOfVolume\WheelsOfVolume.exe
C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
C:\Programmi\Java\jre1.6.0_02\bin\jusched.exe
C:\Programmi\Intel Audio Studio\IntelAudioStudio.exe
C:\Program Files\Intel\IDU\iptray.exe
C:\Programmi\Adobe\Reader 8.0\Reader\Reader_sl.exe
C:\Programmi\ATI Technologies\ATI.ACE\Core-Static\MOM.exe
C:\VeXpLite\MONLITE.EXE
C:\WINDOWS\system32\ctfmon.exe
C:\Programmi\DAEMON Tools Lite\daemon.exe
C:\FRAPS\FRAPS.EXE
C:\Programmi\Bonjour\mDNSResponder.exe
C:\Programmi\McAfee\SiteAdvisor\McSACore.exe
C:\Programmi\Telecom Italia\WanMiniport1st\srvany.exe
C:\Programmi\Telecom Italia\WanMiniport1st\WanMiniport1st_srv.exe
C:\WINDOWS\system32\PnkBstrA.exe
C:\Programmi\Alcohol Soft\Alcohol 120\StarWind\StarWindServiceAE.exe
C:\WINDOWS\system32\svchost.exe
C:\Programmi\File comuni\Softwin\BitDefender Communicator\xcommsvr.exe
C:\Programmi\File comuni\Softwin\BitDefender Scan Server\bdss.exe
C:\WINDOWS\system32\svchost.exe
C:\WINDOWS\System32\alg.exe
C:\Programmi\ATI Technologies\ATI.ACE\Core-Static\ccc.exe
C:\WINDOWS\explorer.exe
C:\Programmi\Trend Micro\HijackThis\HijackThis.exe
C:\WINDOWS\system32\wbem\wmiprvse.exe

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.google.it/
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
R1 - HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings,ProxyOverride = 127.0.0.1;*.local
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O1 - Hosts: 216.107.250.194 nprotect.lineage2.com
O1 - Hosts: 89.186.66.247 L2authd.lineage2.com
O1 - Hosts: 89.186.66.247 L2testauthd.lineage2.com
O2 - BHO: Supporto di collegamento per Adobe PDF Reader - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\Programmi\File comuni\Adobe\Acrobat\ActiveX\AcroIEHelper.dll
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - C:\Programmi\Spybot - Search & Destroy\SDHelper.dll
O2 - BHO: (no name) - {5C255C8A-E604-49b4-9D64-90988571CECB} - (no file)
O2 - BHO: (no name) - {724d43a9-0d85-11d4-9908-00400523e39a} - C:\Programmi\Siber Systems\AI RoboForm\roboform.dll
O2 - BHO: Groove GFS Browser Helper - {72853161-30C5-4D22-B7F9-0BBC1D38A37E} - C:\PROGRA~1\MICROS~3\Office12\GRA8E1~1.DLL
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.6.0_02\bin\ssv.dll
O2 - BHO: Guida per l'accesso a Windows Live - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Programmi\File comuni\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: McAfee SiteAdvisor BHO - {B164E929-A1B6-4A06-B104-2CD0E90A88FF} - c:\PROGRA~1\mcafee\SITEAD~1\mcieplg.dll
O3 - Toolbar: &RoboForm - {724d43a0-0d85-11d4-9908-00400523e39a} - C:\Programmi\Siber Systems\AI RoboForm\roboform.dll
O3 - Toolbar: Veoh Browser Plug-in - {D0943516-5076-4020-A3B5-AEFAF26AB263} - C:\Programmi\Veoh Networks\Veoh\Plugins\reg\VeohToolbar.dll
O3 - Toolbar: McAfee SiteAdvisor Toolbar - {0EBBBE48-BAD4-4B4C-8E5A-516ABECAE064} - c:\PROGRA~1\mcafee\SITEAD~1\mcieplg.dll
O3 - Toolbar: Veoh Web Player Video Finder - {0FBB9689-D3D7-4f7a-A2E2-585B10099BFC} - C:\Programmi\Veoh Networks\VeohWebPlayer\VeohIEToolbar.dll
O4 - HKLM\..\Run: [FuzLez WheelsOfVolume] "C:\Programmi\FuzLez\WheelsOfVolume\WheelsOfVolume.exe"
O4 - HKLM\..\Run: [avast!] C:\PROGRA~1\ALWILS~1\Avast4\ashDisp.exe
O4 - HKLM\..\Run: [SunJavaUpdateSched] "C:\Programmi\Java\jre1.6.0_02\bin\jusched.exe"
O4 - HKLM\..\Run: [SigmatelSysTrayApp] sttray.exe
O4 - HKLM\..\Run: [IntelAudioStudio] "C:\Programmi\Intel Audio Studio\IntelAudioStudio.exe" TRAY
O4 - HKLM\..\Run: [ipTray.exe] "C:\Program Files\Intel\IDU\iptray.exe"
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: [Adobe Reader Speed Launcher] "C:\Programmi\Adobe\Reader 8.0\Reader\Reader_sl.exe"
O4 - HKLM\..\Run: [StartCCC] "C:\Programmi\ATI Technologies\ATI.ACE\Core-Static\CLIStart.exe" MSRun
O4 - HKLM\..\Run: [VIRIT LITE MONITOR] C:\VeXpLite\MONLITE.EXE
O4 - HKCU\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\ctfmon.exe
O4 - HKCU\..\Run: [DAEMON Tools Lite] "C:\Programmi\DAEMON Tools Lite\daemon.exe" -autorun
O4 - HKCU\..\Run: [Fraps] C:\FRAPS\FRAPS.EXE
O4 - HKUS\S-1-5-19\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVIZIO LOCALE')
O4 - HKUS\S-1-5-20\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SERVIZIO DI RETE')
O4 - HKUS\S-1-5-18\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\Run: [CTFMON.EXE] C:\WINDOWS\system32\CTFMON.EXE (User 'Default user')
O8 - Extra context menu item: Compila Modulo - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O8 - Extra context menu item: E&sporta in Microsoft Excel - res://C:\PROGRA~1\MICROS~3\Office12\EXCEL.EXE/3000
O8 - Extra context menu item: Personalizza - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComCustomizeIEMenu.html
O8 - Extra context menu item: RF Barra strumenti - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
O8 - Extra context menu item: Salva Moduli - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.6.0_02\bin\ssv.dll
O9 - Extra button: Inserisci blog - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Programmi\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: Inserisci &blog in Windows Live Writer - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Programmi\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: Invia a OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra 'Tools' menuitem: I&nvia a OneNote - {2670000A-7350-4f3c-8081-5663EE0C6C49} - C:\PROGRA~1\MICROS~3\Office12\ONBttnIE.dll
O9 - Extra button: Compila - {320AF880-6646-11D3-ABEE-C5DBF3571F46} - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O9 - Extra 'Tools' menuitem: Compila Modulo - {320AF880-6646-11D3-ABEE-C5DBF3571F46} - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComFillForms.html
O9 - Extra button: Salva - {320AF880-6646-11D3-ABEE-C5DBF3571F49} - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O9 - Extra 'Tools' menuitem: Salva Moduli - {320AF880-6646-11D3-ABEE-C5DBF3571F49} - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComSavePass.html
O9 - Extra button: RoboForm - {724d43aa-0d85-11d4-9908-00400523e39a} - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
O9 - Extra 'Tools' menuitem: RF Barra strumenti - {724d43aa-0d85-11d4-9908-00400523e39a} - file://C:\Programmi\Siber Systems\AI RoboForm\RoboFormComShowToolbar.html
O9 - Extra button: Research - {92780B25-18CC-41C8-B9BE-3C9C571A8263} - C:\PROGRA~1\MICROS~3\Office12\REFIEBAR.DLL
O9 - Extra button: Barra di ricerca di Encarta - {B205A35E-1FC4-4CE3-818B-899DBBB3388C} - C:\Programmi\File comuni\Microsoft Shared\Encarta Search Bar\ENCSBAR.DLL
O9 - Extra button: (no name) - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\Programmi\Spybot - Search & Destroy\SDHelper.dll
O9 - Extra 'Tools' menuitem: Spybot - Search && Destroy Configuration - {DFB852A3-47F8-48C4-A200-58CAB36FD2A2} - C:\Programmi\Spybot - Search & Destroy\SDHelper.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
O16 - DPF: {5C051655-FCD5-4969-9182-770EA5AA5565} (Solitaire Showdown Class) - http://messenger.zone.msn.com/binary/SolitaireShowdown.cab56986.cab
O16 - DPF: {6414512B-B978-451D-A0D8-FCFDF33E833C} (WUWebControl Class) - http://update.microsoft.com/windowsupdate/v6/V5Controls/en/x86/client/wuweb_site.cab?1179336998000
O16 - DPF: {C3F79A2B-B9B4-4A66-B012-3EE46475B072} (MessengerStatsClient Class) - http://messenger.zone.msn.com/binary/MessengerStatsPAClient.cab56907.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O18 - Protocol: grooveLocalGWS - {88FED34C-F0CA-4636-A375-3CB6248B04CD} - C:\PROGRA~1\MICROS~3\Office12\GR99D3~1.DLL
O18 - Protocol: sacore - {5513F07E-936B-4E52-9B00-067394E91CC5} - c:\PROGRA~1\mcafee\SITEAD~1\mcieplg.dll
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~1\FILECO~1\Skype\SKYPE4~1.DLL
O23 - Service: Adobe LM Service - Adobe Systems - C:\Programmi\File comuni\Adobe Systems Shared\Service\Adobelmsvc.exe
O23 - Service: Apple Mobile Device - Apple Inc. - C:\Programmi\File comuni\Apple\Mobile Device Support\bin\AppleMobileDeviceService.exe
O23 - Service: avast! iAVS4 Control Service (aswUpdSv) - ALWIL Software - C:\Programmi\Alwil Software\Avast4\aswUpdSv.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: avast! Antivirus - ALWIL Software - C:\Programmi\Alwil Software\Avast4\ashServ.exe
O23 - Service: avast! Mail Scanner - ALWIL Software - C:\Programmi\Alwil Software\Avast4\ashMaiSv.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Programmi\Alwil Software\Avast4\ashWebSv.exe
O23 - Service: Admin Works Agent X8 (AWService) - OSA Technologies Inc., An Avocent Company - C:\Program Files\Intel\IDU\awServ.exe
O23 - Service: BitDefender Scan Server (bdss) - Unknown owner - C:\Programmi\File comuni\Softwin\BitDefender Scan Server\bdss.exe
O23 - Service: Bonjour Service - Apple Inc. - C:\Programmi\Bonjour\mDNSResponder.exe
O23 - Service: FLEXnet Licensing Service - Acresso Software Inc. - C:\Programmi\File comuni\Macrovision Shared\FLEXnet Publisher\FNPLicensingService.exe
O23 - Service: InstallDriver Table Manager (IDriverT) - Macrovision Corporation - C:\Programmi\File comuni\InstallShield\Driver\11\Intel 32\IDriverT.exe
O23 - Service: Servizio iPod (iPod Service) - Apple Inc. - C:\Programmi\iPod\bin\iPodService.exe
O23 - Service: McAfee SiteAdvisor Service - Unknown owner - C:\Programmi\McAfee\SiteAdvisor\McSACore.exe
O23 - Service: MSSQL$SONY_MEDIAMGR - Unknown owner - C:\Programmi\Sony\Shared Plug-Ins\Media Manager\MSSQL$SONY_MEDIAMGR\Binn\sqlservr.exe (file missing)
O23 - Service: Network WanMiniport First Position - Unknown owner - C:\Programmi\Telecom Italia\WanMiniport1st\srvany.exe
O23 - Service: NVIDIA Display Driver Service (NVSvc) - NVIDIA Corporation - C:\WINDOWS\system32\nvsvc32.exe
O23 - Service: PnkBstrA - Unknown owner - C:\WINDOWS\system32\PnkBstrA.exe
O23 - Service: ServiceLayer - Nokia. - C:\Programmi\PC Connectivity Solution\ServiceLayer.exe
O23 - Service: SQLAgent$SONY_MEDIAMGR - Unknown owner - C:\Programmi\Sony\Shared Plug-Ins\Media Manager\MSSQL$SONY_MEDIAMGR\Binn\sqlagent.EXE (file missing)
O23 - Service: StarWind AE Service (StarWindServiceAE) - Rocket Division Software - C:\Programmi\Alcohol Soft\Alcohol 120\StarWind\StarWindServiceAE.exe
O23 - Service: TwonkyMedia - PacketVideo - C:\Programmi\Nokia\Nokia Home Media Server\Media Server\TwonkyMedia.exe
O23 - Service: BitDefender Communicator (XCOMM) - Softwin - C:\Programmi\File comuni\Softwin\BitDefender Communicator\xcommsvr.exe

--
End of file - 12943 bytes

Attendi con fiducia la risposta dell'esperto, questo settore non è il mio campo, ti posso solo
suggerire di installare il Service Pack 3, molto utile, e di eliminare tutte le toolbar che hai, esclusa quella di McAfee SiteAdvisor, spesso le toolbar creano intralci e rallentamenti.
Se ti dovesse rispondere r16, fai esattamente quello che ti suggerisce in tutta tranquillità.
Ciao

EDIT: ho letto ora la risposta di r16, sei in buone mani.

scusa l'ignoranza ma è per esser sicuro, dopo aver selezionato questa voce, devo cliccare sul pulsante fix checked?

edit: tenendo aperto il task manager ho notato un consumo della ram esponenziale per quanto riguarda firefox