Mercutio
Fatwah on Western Digital
I had a couple systems for 4-5 years and a laptop for even longer, but my upgrade cycles are shorter now like they were prior to Gulftown. Nowadays it's all e-wasted in a few years. It's too much of a security hassle to re-home them.
Howso? You just don't give up your drives. The Windows licenses are tied to the motherboard, so the only thing you might be out is some small cost for a new place to put Windows.