I want to reinstall Windows 7 as it "broke" and I can't boot a Desktop. Will my files disappear if I reinstall? What should I do, if possible, to avoid that?
Just in case, click on the windows key and search for "Backup and Restore." Connect an external harddrive or even a CD or USB drive with a lot of storage space (greater than 30 gigs, say). Use the "Create a system image" option in the left margin. Specify the drive (i.e., external HD, CD, USB) where you want to save the drive image. Run the drive imaging process. You will now have saved an image of your drive, which you can use to restore all of your files, folders, settings, programs, etc, after reinstalling Windows 7 (if that is indeed necessary).
The files like videos, photos and documents won't disappear.Make sure you don't format or re partition disks containing files you want.However, you'll have to re-install every softwares to make them work on your re-installed OS, except the portable softwares.
Anyway, just backup all the important files to any pendrive or disk before you re-install.