Turn on. Black screen, no icons. Click what is shown and nothing happens. Only thing on black screen is the Recycle Bin top left corner. Troubleshooter said it fixed the No Audio problem it found. Turn off. Turn back on. Same thing. In lower left tray there is Windows icon, a magnifying glass Search icon, a Task View icon, and Play Audio icon, none of which respond. Some icons in lower right tray but also none respond to mouse clicks. Happened after an automatic windows update ran then screen went black. Unplug, plug back in, turn off, restart.....nothing helps. What could be wrong and what do I do? Have had NO trouble with machine since purchased. I have never had anything like this happen though 7 computers in period 1998 on to now. No idea why, what is happening or what to do. Starts and shuts off but nothing shows up and mouse does nothing. Now unplugged and on battery power. Kept pushing power button. Finally came on to a blank blue screen with a moving circle of white dots and says "PLEASE WAIT". 5 minutes now and still same. Plugged back in. No change. Replace mouse battery. Cursor moves around on screen, keys and mouse do nothing. Just the blank blue Please Wait screen. No icons, tray or anything. I am stumped. Nothing seems to work. Finally mouse clicking on screen put various windows up that I do not understand so unplugged cord, shut down, and quit for the night. No cause found, know no solution. It went through series of blue screens that said Do Nothing-Leave Everything To Us and finally a white box that said "C\Windows\System32\Config\System profile\Desktop is unavailable. OK. Clicked OK, box went away, and now black screen with few icons that do not work. Do not know what to do. Any suggestions???????