Exactly. All the drivers for EVERYTHING on the computer are now not able to be used because the HDD is in a different computer. The solution if you want to keep the files intact is to pull the files off of the HDD giving you problems using a secondary HDD. Reformat the drive giving you problems installed in the computer you want it in so that it will load the proper drives with the OS for the MB and other hardware devices.

You can't just slap a HDD with an OS on it into another box. No workie.