One of the first things I found was that I was not able to navigate to C:\Documents and Settings, where I expected to find my user files. I found it is now a "junction point", not a file location. The files I was expecting to find are now in C:\Users. I learned that junction points are placed in the old file locations to be compatible with programs that use the locations now held by junction points. There are many such junction points that apparently were first used in Vista. As I skipped Vista, this was new to me.

See Junction Points (Windows) for Microsoft explanation.
 
A list of junction points is here: Junction Point list

Vista Forum discussion : C:\Documents and Settings is not Accessible