Quote Originally Posted by metavoid

" install a different desktop just to get different resolutions now did you"

Im not sure what you mean. Another windows manager ?
That's exactly what I mean. http://xfce.org/

I just want that my user "A" always runs in 800x600 but root has
1024x768.

Thanks.
You should never login as root. It simply isn't necessary and it is very insecure as well as potentially harmful to your system. For anythihg that needs to be done as root use su while logged in as user. On all of my systems root is not even allowed to log into the desktop.