For some reason the mice on three machines have failed totally. No error on detection is given when the machine is booting up. Recently i discovered the machines had been attacked by the parite (memmory resident) virus. It had infected a lot of the .exe and .scr files. I got a utility from bitdefender which cleaned the virus. So, i'm left with clean machines but non working mice. Could the virus have messed the mice up? The machines are AOpen P4 and run on Win 2000.