I'm having this problem periodically.  I've got an HP desktop, running windows XP home edition.  The computer will just shut down (blank screen).  The top button on the tower will be blinking.  I press that to TURN it off then turn the pc back on.  It happened several times at home this morning, then finally was all right and working properly when I left for work. 

When I got home this afternoon it only happened once.  Any help would be appreciated.  Thank you so much.

Donna in CADonna how old is the machine ? ?
Any issues leading up to this point ?
Have you installed any NEW hardware/software recently ? ?Also...

Disable "Restart on error" feature...

1. Right-click My Computer, and then click Properties.
2. Click the Advanced tab (Vista: click Advanced system settings).
3. Under Startup and Recovery, click Settings to open the Startup and Recovery dialog box.
4. Clear the Automatically restart check box, and click OK the necessary number of times.
5. Restart your computer for the settings to take effect. Thanks so much broni.  I'm almost positive this fixed the problem.

Donna in CA
If its restarting then it wouldnt have.  Just gives you the change to fix it.  The computer doesn't restart itself, was just shutting down and I had to manually restart it.  Sorry I wasn't clear on that.  I'm not real computer LITERATE, and I get confused on some of this stuff.

Donna in CA Does the computer operate fine? No errors, or other issues?Computer seems to be fine now since I did the "Disable "Restart on error" feature.  That was the only problem I had with the computer.  Thanks again.

How do you get colored text in your POSTS?  I can't seem to figure it out.

Donna in CAwere it says change color in the top near the bullet list.Thank you!  WELCOME