LCD monitors contain millions of pixels, each one composed of three subpixels: red, blue, and green. When all three are on, a pixel looks white. Other combinations create other colors. A pixel can become stuck showing one hue. But you can fix this.
Determine whether the pixel is just stuck or completely dead. If it shows only black, it's probably inoperable. If it shows a solid color, though, it may be stuck, and you may be able to shock it back into operation.
Make sure that your LCD is clean--spray a few blasts of compressed air, and follow up by wiping with a scratch-free cloth and screen cleaner.
Verify that your PC is outputting the image in your LCD's native resolution so you can identify pixels more easily. Open Start•Control Panel• Display, click the Settings tab, and adjust the resolution. (Consult your display's documentation, if necessary.)
In UDPixel, increase the Run cycle option to 4 seconds, and click the Run cycle button. The display will cycle through red, green, blue, black, white, and yellow. A stuck pixel should be visible against every hue but the one it's stuck in; unchanging dots are problem areas. Click to stop the color cycle.
For multiple pixels, increase the Flash window number by 1 for each stuck pixel.
Otherwise, click Start; a small, 5-by-5-pixel box will appear. Reposition the box around the stuck pixel, and wait 15 to 20 minutes. Click Reset to turn it off, and repeat the color cycle to see if the pixel has cleared.
If the problem persists, check your LCD warranty to see if you can replace the screen.
If you can't make such a replacement, try applying direct pressure. Wrap the tip of a PDA stylus or similar object in a scratch-free cloth, and use UDPixel to find the trouble spot.
Align the covered tip of the stylus directly over the uncooperative pixel. Turn off the screen, and gently (carefully) apply pressure for 5 to 10 seconds. Turn the screen back on, and check the pixel.
If it's still stuck, repeat steps 9 and 10, and even step 7. If you get no results, try wrapping the rounded, plastic end of a marker pen in a scratch-free cloth, and gently tap the afflicted area a few times.
If you're lucky, one of these tricks will revive the pixel.