I’ve done it, and things were just sort of off for a bit. Are you sticking with the same brands as before? Sometimes that makes the transition easier as they could have some of the same shit. If you reinstall you’ll most likely need a new cd key. If you go the eBay way of getting a key, do it early in the morning. I’ve had the best luck of the accounts sending me the key before eBay kills the account in the morning.

But honestly, backup, make yourself a windows boot stick, then do the swap and boot up to see what happens.