I changed my display settings and now I have a grey screen?

I'm assuming your computer has Windows 7 installed. This work for your situation also.

When you install a new device driver, you change the Windows 7 configuration. The next time you restart your computer, Windows 7 tries to use the new configuration. However, sometimes when you install a new device driver, the whole thing locks up and stops working, usually because whatever driver you installed wasn’t as compatible with Windows 7 as you thought.

If that happens to you, the only way to get things flowing again is to restart Windows 7 and tell it to ignore the changes you made.

If your computer is still working (just not correctly), click the Start button, click the right-facing arrow to the right of the little lock, and choose Restart.

Windows 7 restarts. Skip to Step 3.

If your computer isn’t responding, press the power button to turn it off. Wait a minute or so. Press the power button again to turn the computer back on.

If that doesn’t work, try pressing the button again and holding it in for several seconds. If that doesn’t work either, disconnect the power cord; wait a few seconds, and then plug it in again.

If you’re working with a laptop, you may even need to remove the battery.

As soon as the computer starts to come back to life, press and hold down F8.

Windows 7 displays a menu of special startup options you can choose.

Use the up-arrow and down-arrow keys to move the menu’s highlight to Last Known Good Configuration (Advanced), and then press Enter.

The mouse won’t work at this screen.

Finish the startup procedure as usual.

Your computer should load successfully, and Windows 7 will discard the “new” screwed-up configuration and return permanently to the last known good configuration.

If it doesn’t rev back to life, you’ll want to get out your handy System Repair Disc and try going back to the last System Restore Point.