Digital photography & design software: Photoshop Elements 5 and Windows XP Pro 64 bit-flicker/freez

Photoshop Elements 5 and Windows XP Pro 64 bit-flicker/freez

I have been using PSE5 for a couple of years w/XP Media Center without any problems. Now have 64 bit OS and thought everything okay for the last couple of months but today PSE locked up on the File Tabs. I don't know what that is either, LOL. What I mean is, it would let me choose, move, minimize, etc. in the editor but would not let me save a file, close a file, close the program, use CTRL/Alt/Delete, use any Ctrl keys, and finally would not let me shut down the computer or restart it! Help! I went to Adobe but could find no help at all. This program is my life! What in the world could be the matter?