display blacks out every few seconds

my monitor display blinks or should i say blacks out every 15 or 20 seconds. it blinks for a fraction of a second. this is really annoying. i check the display settings couldn't find problem. need help

Try updating your driver, try a windows update, then select the optional tab, there usually in there. If that doesn't work, try a different vga to the screen, the one you are using maybe faulty, and if that doesn't work, try the computer on a different screen, it could be faulty.

still blinking

I updated the driver, no change & the vga cable checked out ok. is there anything else i can try