Repair corrupted Windows w/o formatting HDD

So, I’ve picked up a HDD from my colleague that cannot boot on its own. Something in WINDOWS/System folder is corrupted. So I was wondering if there’s a tool that would find the erroneous file which could help me repair it (make it bootable) without formatting the entire HDD since there’s some important data there. I know about Hiren’s Boot CD and other Emergency Boot tools, but I mounted the HDD on my PC and now I have full access to it. Is there any tool for Windows to self-diagnose?
P.S. Refrain yourself from trolls like “Run Linux” or “Run Mac” even though I agree with those, that is not the option in this case.
Cheers and thanks in advance, Nitro!
Answer #1
Did you try the most obvious option..Booting with Windows 7 Install DVD (Assuming you have Win7) And doing a Windows repair?
And there is no need for the P.S comment!!!
Answer #2
.... since there's some important data there ....
.... I mounted the HDD on my PC and now I have full access to it ....
Now that you have full access to the data, just copy the important data onto another working drive.
Fixing a corrupted Windows install is probably a bad idea in the long run. It will most likely just corrupt again.
Answer #3
I agree with Ashley’s opinion, I was hoping there’d be someone smarter than me who could make something that would be pain-free. The problem is that there’s an abundant amount of incompatibility between my coworker’s PC and mine but I won’t bother you with that, I’ll get through that hassle. Thanks and consider it closed!
Cheers