why does my hard drive work in one computer but not the other

[tompkinsdevon]

when I put my hard drive into my new computer it continuously looped it works fine in another computer but not my new one the original computer fried but it's still a good version of Windows 7 so the hard drive is still good any help would greatly appreciated

 

[kanewolf]

Because the motherboard is different. The windows installation is configured for the old motherboard. You might be able to coax it to boot or you may just have to reinstall everything.

 

[Paul NZ]

Would be nice if you could chop and change hardware when and if you felt like it. But you cant.