Reading about reinstalling, I had a thought. My dual boot is Vista first, and now 10. Works fine, but now, the dual booting choice is on a 10-like screen not just a BIOS affair. Looks cool, but what the heck happens when you need to do a full reinstall of 10?
It seems to me you'll have no way of getting to that boot-specific partition, so a format followed by a clean install becomes a bit of a mystery.