I have windows 8 and ubuntu 12.04 installed alongside, within a partition each. Since I had upgraded from windows 7 after having installed ubuntu, I had no problem with the ubuntu installation back then. But, because of the upgrade, windows 8 works with a plethora of problems, and I want to format and install a clean version, maybe with 8.1. I want to keep the ubuntu partition as is, if possible, or I can format that as well and upgrade to 13.04, possibly. Which is the easier way to go, and what are the possible problems I might encounter?