I changed some settings and can't find my desktop

Hi, I suspect someone is hacking into my computer and so in an attempt to see if I can find some setting to prevent this, I made some changes to my internet explorer settings, and I opened my windows explorer, went to documents and settings ( I had admin, all users, and Fidel - my user name). I right clicked on my user name and played with the settings. Now I've lost my desktop and I have a new user name (fide.fidelcomputer) I see my username still in the tree, and all my files and old desktop. I still need to log on with the same name and password, I just now have a new desktop that isn't configured with any programs. I obviously need to recover my old desktop. Please help.