Switched HDD, Windows won't boot.

[Christopher_16]

I switched the HDD between two computers, both pre built (HP and Dell). Both PCs came with Windows, one with 7 and the other with 8.1. The computer that had windows 7 won't boot. Can someone please help?

 

[kanewolf]

Windows, on the disk, knows about the hardware it was installed on. When you put a configured windows disk into a different set of hardware (motherboard) there is no guarantee it will work. That is obviously the case. Either put the disks back the way they were or reinstall the OS.

 

[popatim]

Yep, clearly a case of 1- wrong drivers, and 2 - wrong boot style. The win 8 would be UEFI/GPT boot which is way more secure, even at the boot level, then the old 7 OS.