I changed out the harddrive in my computer because it was my friends old computer which he didn't want anymore, but had been using the Ubunto OS, which i know nothing about. As well as me having another harddrive in my other, much less powerful computer which has all my data on it. The problem i'm experiencing is the monitor not receiving a signal from the computer, not even a bios, when i have the 'new' harddrive installed, or with no harddrive installed, however when i plug in the old harddrive with Ubunto on it, it boots into Ubunto just fine, but still shows no bios. I cant think of anything that would cause this hardware wise. Is there anyway i can get the computer to recognize the 'new' Harddrive and Win 7 OS?

Hmmm, this is pretty weird, but you can try a couple of things. did you try unplugging all HDs? did you try replacing SATA cables? is the new hard drive much different than the old one (space wise)?