The Presario computer with WinXP w/SP3 boots up with no errors but the mouse & keyboard do not respond. Pointer for mouse does not move. Keyboard does not do anything; even CTRL-ALT-DELETE has no effect. Cannot get into F2, F8 or F12. Computer boots up by power button; displays desktop. Can only turnoff by power button. What should I look for & where? I’ve got the hard drive in my Dell as a slave so I could work on this for my friend; she is legally blind so this is Pro-Bono. Thank you for your help!