closing laptop lid; turn off display?

Check your power management options. You might have set it to do nothing when you close your lcd. Try playing around with the different options. That might solve your problem.

Go to Control Panel > Power Options > Advanced tab > under "when I close my laptop lid", choose "Do Nothing"

This will have the laptop only turn off the screen but not do anything else when you close the lid. To test it out, you can press that little button on top of the numlock led light (near the "mute" button). Pressing that will act like you are closing the lid. Wait a few seconds, then the screen should turn off, but everything else should stay the same.