cannot access any application

Dear Vista users,

I have a serious problem in my Vista Ultimate. I changed my current account,
reboot and than the problem started. I am signed as admistrator, but I cannot
access any application or even restart or turn off my computer.

I says "You don't have an right to shut down the computer."

Right know I cannot do anything. I tried to change the set up again but
again Vista repeats the same pop up windows "you don't have a right to
do......"

Is here anyone who can help to solve this problem. I would appreciate that.

Thank you

Jan Holicky