Continuing with the OT theme...
As a frequent beta tester of MS OS products, I find myself formating and reinstalling all the time. I've adopted the procedure of setting up multiple partitions on the HDD. A 40GB C: partition should be plenty for most users, with the balance of the drive as D: I use the D: partition as storage. I actually install games to a D:/Games directory, Photos to D:/Photos, etc. When I need to reinstall, for whatever reason, I format the C: partition and reinstall.
Now I know that most of you do not need to do this frequently, but installing that way the first time and putting the important stuff on a separate partition, along with proper security and backup procedures in place, you are better prepared should anything occur.
There are several techniques and none are perfect. This is only the one I use.