Transfering HDD

my computer was basically fried, so im upgrading all my parts since its outdated. But when i rebuild my computer, am i able to use the old hdd and use the OS? i still want use the files on the hdd

Depends on how you want to use the drive. If your buying a new faster drive, then just hook up the old one and use it as a data drive. If you want to reuse it as your boot drive, there will be some issues.

Every different chipset company uses their own special way to talk to the harddrive. Nvidia uses their own, as does AMD, ULI, Via, SiS (are they even still around???) etc. If you go from the Nvidia NF4 to an Intel P45, the drivers windows last knew to use (Nvidia) won't work. If you new you were going to do this you could have simply changed the driver to "windows default", but thats not possible on "basically fried" computers.

The solution is to do a repair install of windows. This will wipe all the old drivers and load the new ones. You won't lose any data files, though some programs will want to reactivate. Depending on the age of the drive, you are probably a lot better off just buying a new one.

BTW, be aware you can't just transfer a drive from an OEM computer to a home built one. Windows won't allow it.