My laptop has recently crashed and now I cannot reboot. When I try it hangs for a while and then gives an error message saying that it cannot find the isapnp.sys file or it is corrupt. It then tells me to repair it using the original OS disk in the recovery console. I have followed the instructions on the Microsoft site to repair the file but I get an 'access denied' error when I try to copy the file. I can't boot in safe mode either as I get the same isapnp.sys error message. I tried a repair installation of the OS but the 'r' option was not available. I recently had a trojan virus which I thought I had cleared up. I was running another virus check to make sure everything was clean when it crashed. Does anyone have any ideas on how I can fix this? Many thanks.