Hi guys,
Ive recently purchased a Dell XPS 1640 laptop. I want to download stuff but leave the lid closed, but every time I do so, it goes into sleep or hibernate mode and shuts down the internet connection. How do I disable to sleep mode so that it can stay connected to download my stuff? Ive already set (under Power Management) "Lid Closed" to Do Nothing and set the Wireless card to maximum strength. Is there some other configuration Im missing out?

You might need to make sure that the action on lid close is disabled for both battery & power. If that doesn't do it then you might also have to disable hibernation. To do that, browse to command prompt: start menu, all programs, & accessories. Right click on command prompt & select run as administrator. Hit the box to allow or provide an administrator's password. In the black box paste powercfg -h off & hit enter. Now you can close the box & try again.

Hi braddor...Just adding on to towns post. Please confirm that you've done the following...
1) Get into "Control Panel"
2) Double-click "Power Options"
3) Start "Choose what closing the lid does"
4) For the "When I close the lid" section change the option from "Hibernate" to "Do nothing" on both the "On Battery" and "Plugged in" columns.

You can now close the Laptop lid and your Laptop should stay on. Many of my Laptop users at work have Docking Stations and just want to use the external Monitor...this is the option to use.

Do you have Dell "QuickSet" installed? If so make sure under "Internal Network Card Power Management" you have it set to "Always activate on battery".

Not sure if this will help but...There is an option in the Properties if your Wireless card under the "Power Management" tab to "Allow the computer to turn off this device to save power". Remove the check mark if selected.