Logfile of HijackThis v1.99.1
Scan saved at 16.20.57, on 05/10/05
Platform: Windows 98 SE (Win9x 4.10.2222A)
MSIE: Internet Explorer v6.00 SP1 (6.00.2800.1106)

Running processes:
C:\WINDOWS\SYSTEM\KERNEL32.DLL
C:\WINDOWS\SYSTEM\MSGSRV32.EXE
C:\WINDOWS\SYSTEM\MPREXE.EXE
C:\WINDOWS\SYSTEM\MSTASK.EXE
C:\WINDOWS\SYSTEM\mmtask.tsk
C:\WINDOWS\EXPLORER.EXE
C:\WINDOWS\TASKMON.EXE
C:\SBPCI\CTMIX32.EXE
C:\WINDOWS\SYSTEM\HPZTSB08.EXE
C:\WINDOWS\SYSTEM\SYSTRAY.EXE
C:\PROGRAMMI\HEWLETT-PACKARD\HP SOFTWARE UPDATE\HPWUSCHD.EXE
C:\PROGRAMMI\HEWLETT-PACKARD\DIGITAL IMAGING\BIN\HPOTDD01.EXE
C:\WINDOWS\SYSTEM\SPOOL32.EXE
C:\PROGRAMMI\ATNOTES\ATNOTES.EXE
C:\WINDOWS\SYSTEM\WMIEXE.EXE
C:\PROGRAMMI\MAXTHON\MAXTHON.EXE
C:\PROGRAMMI\MAXTHON\MAXTHON.EXE
C:\WINDOWS\SYSTEM\DDHELP.EXE
C:\PROGRAMMI\HIJACKTHIS CART\HIJACKTHIS.EXE

R0 - HKCU\Software\Microsoft\Internet Explorer\Main,Start Page = http://www.autobus.it/
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName = Collegamenti
O2 - BHO: AcroIEHlprObj Class - {06849E9F-C8D7-4D59-B87D-784B7D6BE0B3} - C:\PROGRAMMI\ADOBE\ACROBAT 5.0\READER\ACTIVEX\ACROIEHELPER.OCX
O2 - BHO: (no name) - {53707962-6F74-2D53-2644-206D7942484F} - C:\Programmi\Spybot - Search & Destroy\SDHelper.dll
O3 - Toolbar: &Radio - {8E718888-423F-11D2-876E-00A0C9082467} - C:\WINDOWS\SYSTEM\MSDXM.OCX
O4 - HKLM\..\Run: [TaskMonitor] C:\WINDOWS\taskmon.exe
O4 - HKLM\..\Run: [CreativeMixer] C:\SBPCI\ctmix32.exe /T
O4 - HKLM\..\Run: [HPDJ Taskbar Utility] C:\WINDOWS\SYSTEM\hpztsb08.exe
O4 - HKLM\..\Run: [SystemTray] SysTray.Exe
O4 - HKLM\..\Run: [HP Software Update] C:\Programmi\Hewlett-Packard\HP Software Update\HPWuSchd.exe
O4 - HKLM\..\Run: [DeviceDiscovery] C:\Programmi\Hewlett-Packard\Digital Imaging\bin\hpotdd01.exe
O4 - HKLM\..\Run: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - HKLM\..\RunServices: [SchedulingAgent] mstask.exe
O4 - HKLM\..\RunServices: [LoadPowerProfile] Rundll32.exe powrprof.dll,LoadCurrentPwrScheme
O4 - Startup: Microsoft Office.lnk = C:\Programmi\Microsoft Office\Office\OSA9.EXE
O4 - Startup: EPSON Status Monitor 3 Environment Check.lnk = C:\WINDOWS\SYSTEM\E_SRCV03.EXE
O4 - Startup: ATnotes.lnk = C:\Programmi\ATnotes\ATnotes.exe
O9 - Extra button: (no name) - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra 'Tools' menuitem: Sun Java Console - {08B0E5C0-4FCB-11CF-AAA5-00401C608501} - C:\Programmi\Java\jre1.5.0_02\bin\npjpi150_02.dll
O9 - Extra button: Messenger - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\MSMSGS.EXE
O9 - Extra 'Tools' menuitem: MSN Messenger Service - {FB5F1910-F110-11d2-BB9E-00C04F795683} - C:\Programmi\Messenger\MSMSGS.EXE
O12 - Plugin for .spop: C:\PROGRA~1\INTERN~1\Plugins\NPDocBox.dll
O12 - Plugin for .NPSSView: C:\Programmi\Seagate Software\Viewers\ActiveXViewer\NPssView.dll
O15 - Trusted Zone: www.autobus.it
O16 - DPF: {4D8DF501-99FB-41EE-8077-BB77C8D0A8F2} (GestoreStampa Object) - https://www.autobus.it/V3_0_9/stampax/StampaX.cab
O16 - DPF: {EFCF5E68-BDEC-4068-92B9-E09F57077804} (CLIENT_SETTIME.UserControl1) - https://www.autobus.it/PLUSMANAGER_SQL/SincronizzazioneOra.ocx
O17 - HKLM\System\CCS\Services\VxD\MSTCP: NameServer = 192.168.10.100

Aspettando il responso di Alfonso mi faccio un po'i fatti tuoi(se me lo permetti)Mi sembra che tu non abbia ne'antivirus ne' firewall ,o almeno non sono attivi.
Accetta un consiglio da Amico e vai nella sez. software,sicurezza e scarica quello che puo' fare al caso tuo e che ti protegga.