when is C: not C:?

I have had W7Pro installed for about a year on my 'games' machine, and recently put W7 Home Premium on my older 'works' machine. When I recently upgraded from Firefox4 to 5 on the games machine I was getting flashing black screens, whereas on the works machine it installed without any problems. I tried a number of other browsers on the games machine and found that most of those which use the gecko engine would not run properly - so I deduce there is a problem with my configuration.

I have decided to reinstall the OS on the games machine to see if that might fix the problem, but I want to keep my game saves and a few other docs. I only intend to reformat C: - but am unsure about the libraries. My question is this -

Are the various libraries in Windows 7 the actual source of the contents that appear in them, even though the software they relate to is installed on another logical drive, or do the simply collate and gather the information from other areas?

For instance, I have a folder entitled My Music on G:, but it appears in the C: Library list under my profile.

The libraries do not actually store their contents physically, they just appear to. You can alter the included locations. So, the folder called My Music on your computer is physically on G:, if you remove that drive/folder from the included locations of the library, no harm will come to your musid because its on G:. The purpose of libraries is just to give a unified view of similar folders (music/docs/pics/videos) scattered on the hard drive.

thank you Bill -exactly what I wanted to know :)

that is what I did logicearth - I didn't see any option to format anyway. Still getting used to W7. It cured my problem so that is good but now I have to put the games back on and get things looking the way I like :)

You will only get the Custom install Drive Options to Create, Delete or Format partitions if you boot the installer. Clean Install Windows 7

ahhh, right... don't think I noticed that screen. Very helpful gregrocker, thank you :)