stop usb viruses from spreading

Window XP, Vista, or other version of windows

1. Click Start, click Run, enter gpedit.msc (launch Group Policy Editor);
2. XP users: Open Computer Configuration | Administrative Templates | System,
Vista users: Open Computer Configuration | Windows Components | AutoPlay Policies;
3. Find Turn Off AutoPlay in the right-hand pane and double-click it;
4. Choose Enabled and set it for All drives.

Or, in any Windows version:
1. Launch the Registry editor (Start | Run | regedit);
2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\
CurrentVersion\Policies\Explorer;
3. Double-click NoDriveTypeAutoRun in the right-hand pane and set its value to hexadecimal FF.