Guys, STOP HARPING ON THE UPGRADE INSTALLS! That is not likely to be the source of his problems, considering that I have upgraded from the Beta to Build 7000 to Build 7033 to build 7053 to 7077 to now, 7100 on x86 without a problem (x64 just won't install over a x64 Vista build period).
Since I've now done that on 10 computers..... if he is having problems it is NOT because of the upgrade. Let me put it bluntly: IT IS OVERWRITING 99.99% OF THE FILES IT IS UPDATING!
When an upgrade is doing that..... there is no reason for it to be giving people problems, and it is mostly likely not the upgrade that is giving him the problems.
The things I would suggest to him: try going to the C:\Users\*your name*/My Documents directory manually. If your files are there...... then the location things in Documents has gotten f'ed up somehow, so see which locations are being listed in Documents. If it doesn't have C:\Users\*your username*\My Documents (Music, Pictures, Video) listed.... add it to the locations thing.
I personally had this problem when somehow the locations for Pictures in the Libraries thing I got messed up..... I though I had lost all my 30 GB's of pictures... no, it was just that the locations for Pictures had gotten messed up and My Pictures wasn't listed anymore.