1.) If you can, try swapping out the monitor for another one and see if the problem continues.
2.) Try updating the driver for your integrated graphics by clicking here.
3.) Try disabling the Aero interface temporarily.
4.) Try lowering the resolution on your monitor temporarily.
The last two address the possibility that the integrated graphics are not able to consistently handle the current level, and reduces the strain placed on the chip. Both can be controlled through Control Panel->Appearance and Personalization->Personalization.
Let us know how it goes.
John
I have an HP desktop A1720n that came with Vista installed. I'm using my older NEC flat screen monitor. I have 1024MB memory. My monitor went black for a few seconds while I was attempting to read mail on a Yahoo site. This has happened for a shorter time while I was playing a game in the past. AVG was scanning at the time this morning. This scares me when it happens because I wonder if it will go back to normal. The "blackout" seemed much longer today. I can live with this as long as I know my computer isn't "dying." Thank you.

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