Conventional wisdom says if you pull a drive from one system and stick it in another, you should rebuild the o/s from scratch, to prevent hardware compatibility issues. Even more so if you go from an Intel/Nvidia powered laptop to an AMD/ATI desktop (with Gigabyte motherboard).
I decided to test this theory and found to my surprise that aside from a message that said something along the lines of "one moment, setting up devices" on first Windows boot, I was able to boot into the o/s and carry on as if I was on my laptop still without any other intervention whatsoever. Device Manager reported the various hardware components, including things like USB 3 controller which didn't even exist in the laptop, as working properly.
I should add Wndows 8 was the o/s.
Is anyone else surprised and is there anything I should be worried about? I have since uninstalled the Nvidia drivers and installed the proper ATI ones but otherwise have done nothing. The only problem I have is an unbearably loud stock AMD CPU fan (5000rpm+ on full load) which I think is completely unrelated - and will be replaced in due course.
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Yes, if it was an OEM copy of Windows, it may decide that it needs to be activated again and refuse to re-activate. Also, just because it worked doesn't mean it is a good idea. You really should reinstall the OS. No, it is not always required, but it is always a good idea.