Unless you can be certain that the bogus installation is from a clean copy with the MS hologram, what came with the disk is suspect. In other words, if it's just a licensing infraction where such as a duplicate of another installation, the better choice is probably to start from scratch with the known legal copy. As well, make sure it's a retail and not OEM copy.
Hello. A friend of mine have a pc with invalid windows 7 installtion (I get a message that that I may be a victim and so on...).
I have a real original windows 7 pro copy that is still new and wasn't registered yet.
Can I register the bad copy with the key of the good one so it will be legal and she want need to reinstall windows 7 (because then she will need to install all the other programs she already install on it).