sorry for the confusion guys.I will go from the start. My PC has a 20gig hard drive which is almost full and it is running Windows XP and the drive is not partitioned. I am trying to put in a second hard drive from an old PC which is 20 gig running Windows ME and does have a partitioned hard drive. I have set my old drive to master and the new one I am putting in I have set to slave. When I reboot the PC it notices the 2 hard drives and says press F1 to save changes but after that all it says is "missinig operating system" hope this is a bit clearer, sorry for the confusion. If anyone can help I would very greatful as I have just purchased a DVD writer and cant wait to get this baby in too.