Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 16.29.44, on 27/04/09
Platform: Windows 98 SE (Win9x 4.10.2222A)
MSIE: Internet Explorer v5.50 (5.50.4134.0600)
Boot mode: Normal

Running processes:
C:\WINDOWS\SYSTEM\KERNEL32.DLL
C:\WINDOWS\SYSTEM\MSGSRV32.EXE
C:\WINDOWS\SYSTEM\MPREXE.EXE
C:\WINDOWS\SYSTEM\mmtask.tsk
C:\PROGRAMMI\ALWIL SOFTWARE\AVAST4\ASHSERV.EXE
C:\WINDOWS\EXPLORER.EXE
C:\PROGRAMMI\TRUST\240T\MOUSE32A.EXE
C:\WINDOWS\SYSTEM\SYSTRAY.EXE
C:\WINDOWS\TASKMON.EXE
C:\PROGRAMMI\ALWIL SOFTWARE\AVAST4\ASHWEBSV.EXE
C:\PROGRAMMI\ALWIL SOFTWARE\AVAST4\ASHMAISV.EXE
C:\WINDOWS\SYSTEM\WMIEXE.EXE
C:\WINDOWS\SYSTEM\RPCSS.EXE
C:\WINDOWS\SYSTEM\DDHELP.EXE
C:\WINDOWS\SYSTEM\WBEM\WINMGMT.EXE
C:\PROGRAMMI\HIJACKTHIS\HIJACKTHIS.EXE

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Bar = http://arianna.libero.it
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = about:blank
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://www.libero.it
R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Local Page =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page =
R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Window Title = Microsoft Internet Explorer
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: Yahoo! Toolbar Helper - {02478D38-C3F9-4EFB-9B51-7695ECA05670} - C:\PROGRAMMI\YAHOO!\COMPANION\INSTALLS\CPN\YT.DLL
O2 - BHO: (no name) - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - (no file)
O2 - BHO: SSVHelper Class - {761497BB-D6F0-462C-B6EB-D4DAF1D92D43} - C:\Programmi\Java\jre1.5.0_16\bin\ssv.dll
O2 - BHO: AskBar BHO - {201f27d4-3704-41d6-89c1-aa35e39143ed} - C:\PROGRAMMI\ASKBARDIS\BAR\BIN\ASKBAR.DLL
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\PROGRA~1\SPYBOT~1\SDHELPER.DLL
O3 - Toolbar: Yahoo! Toolbar - {EF99BD32-C1FB-11D2-892F-0090271D4F88} - C:\PROGRAMMI\YAHOO!\COMPANION\INSTALLS\CPN\YT.DLL
O3 - Toolbar: @msdxmLC.dll,-1@1040,&Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\SYSTEM\MSDXM.OCX
O3 - Toolbar: Ask Toolbar - {3041d03e-fd4b-44e0-b742-2d9b88305f98} - C:\PROGRAMMI\ASKBARDIS\BAR\BIN\ASKBAR.DLL
O4 - HKLM\..\Run: [FLMOFFICE4DMOUSE] C:\Programmi\Trust\240T\\mouse32a.exe
O4 - HKLM\..\Run: [ScanRegistry] C:\WINDOWS\scanregw.exe /autorun
O4 - HKLM\..\Run: [SystemTray] SysTray.Exe
O4 - HKLM\..\Run: [TaskMonitor] C:\WINDOWS\taskmon.exe
O4 - HKLM\..\Run: [Tweak UI] RUNDLL32.EXE TWEAKUI.CPL,TweakMeUp
O4 - HKLM\..\Run: [avast! Web Scanner] C:\PROGRA~1\ALWILS~1\AVAST4\ASHWEBSV.EXE
O4 - HKLM\..\Run: [ashMaiSv] C:\PROGRA~1\ALWILS~1\AVAST4\ashmaisv.exe
O4 - HKLM\..\RunServices: [avast!] C:\Programmi\Alwil Software\Avast4\ashServ.exe
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Restrictions present
O6 - HKCU\Software\Policies\Microsoft\Internet Explorer\Control Panel present
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\PROGRAMMI\JAVA\JRE1.5.0_16\BIN\SSV.DLL
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\PROGRAMMI\JAVA\JRE1.5.0_16\BIN\SSV.DLL
O12 - Plugin for .wav: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin.dll
O12 - Plugin for .mp3: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin4.dll
O12 - Plugin for .mov: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin.dll
O12 - Plugin for .mid: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin2.dll
O12 - Plugin for .png: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin5.dll
O12 - Plugin for .cgi: C:\PROGRA~1\INTERN~1\PLUGINS\npqtplugin5.dll
O14 - IERESET.INF: START_PAGE_URL=http://www.libero.it
O16 - DPF: {3D54FEE0-CE46-11D4-8288-0050BA6A5ABF} (WebPie2 Class) - file://C:\Programmi\NewSoft\Presto! Mr.Photo 3\CardExpr\iepiev20.cab
O18 - Protocol: ssp - {1E8068DE-05AD-11D4-ACC8-EF447469245C} - C:\PROGRAMMI\OFFLINE COMMANDER\SSP.DLL

--
End of file - 3899 bytes

Ciao devi aggiornare internet explorer se lo usi poi devi controllare questa voce
O18 - Protocol: ssp - {1E8068DE-05AD-11D4-ACC8-EF447469245C} - C:\PROGRAMMI\OFFLINE COMMANDER\SSP.DLL

dovrebbe essere una DLL Zylox Software,ma non lo conosco.
Qualche esperto ti dara' altre indicazioni.