This should really be in tech talk not tech help since it is a discussion and not a request for help - however -
Not only have I reinstalled windows keeping my steam files - but I have also installed multiple operating systems keeping my steam files (XP and Vista).
Please do tell Lifter some more information because the situation is making me curious. Also it may lead to the discovery of what went wrong. As an example I will start.
---------------------------------------------------
My computer: (as seen by Windows XP)
C: (Windows XP)
D: (Windows Vista)
E: (Applications)
F: (Games)
G: (Storage)
H: (DVDRW)
I: (DVDROM)
J: (virtual drive)
So, after having XP installed, I installed my games and programs, as well as downloads to the appropriately named partitions. Steam was installed in F:
I then installed Vista onto my second partition (The one XP calls D

. After Vista was installed It calls the second partition (where it is installed) C:, and it calls my first partition (where XP is installed) D:. - Leave it to windows to do what it wants -
Now in Vista - I can play steam games without having to redownload them. I sometimes have to reinstall steam but the programs all statyed and stuff.
So do tell, what procedure did you take, and how is your system set up. Just because I am curious.
P.S. you could also have coppied the screenshots into their own folder ont hat alternate partition.