Panic my Desktop changed to Server help is needed

[hoboy]

I was using ubuntu 11.04 then I open some docs in LibreOffice then the machine froze, I had to manually stop and restarted, i had to to use recovery, then I said yes to something, then when the machine started instead of desktop at the starting up message the place where one can chose recovery, is it is written Server, when it does started all the screen backround have have changed to a different skin.
How can I get back to my old desktop ?