I'd highly suggest you run some some integrity checks on that drive to make sure it won't fail later. HDD's don't get corrupted just because.
As to drivers make sure you're getting the right OS type from the dell site.
If you install windows on a HDD on one PC it most certainly won't boot when you move it to the other PC. This is because the drivers that windows needs in order to run are completely different for your PC and your friend's laptop. If you'd have installed it from his laptop then put it in your PC...
You cant get a much better gaming experience and 10 times better overall sound quality for less than $150 with an audio technica AD700 and a clip-on zalman mic. All "gaming" headsets out there are pure rubbish.