Perhaps it's because I cut my teeth on Unix, but one of the (many) bad design decisions that Microsoft has made with Windows is the practice of dumping everything in the same partition as the operating system, which makes backing up your data, upgrading and reinstalling the OS far more complicated than it needs to be.
It won't help you this time, but if you do start from scratch, you might consider creating a separate partition and placing your personal programs and data there. That will greatly facilitate future reinstallations, because you can wipe the OS partition without affecting the vast majority of your data.
I have heard of programs that claim to automatically preserve settings during a reinstall, but these rarely provide details of how they work. (Even Windows itself offers a "refresh" option.) Frankly, though, whenever I must go through the hassle of reinstalling Windows to get a fresh start, I want my start to be
completely fresh.
