I'm pretty sure this a licensing problem.
I have a couple of SATA hard drives with copies of Windows 7 Pro on them.
I tried to put them in an old Dell OptiPlex GX520. This chassis shows it as Windows XP as the last supported O/S.
The drives try to boot to the Win 7 system but fail shortly after the POST. After a second attempt, it comes up to the Launch Recovery option screen. I run that, and then it asks to be able to connect to Microsoft to help correct the problem. I have yet to do that as if I need to pay to re license these drives on a different chassis they were installed on, I want to be sure they are healthy first.
In theory, this should run on the OptiPlex GX520, but slowly, but I have seen Win 7 machines run on lesser resources.
Do you think I'm looking at licensing issues or hardware incompatibility?