My Dell PP281 has been slow lately but today it has been really stuck on a screen saying "Logging off". I tried control alt delete, pressing the power on button above the keyboard, and shutting the lid (I had set this to shut down when lid is shut), and none of these things works. It just keeps on logging off, logging off, etc. Truly mysterious is the fact that I went through the proper shut down process last night. I admit I left it once I had confirmed shut down and didn't close the lid or look at it again until this am when I pressed the power button to turn it on -- the button light was off. Any ideas of what to do?