external monitor

Yes, but you'll have to set it each time you connect it again if you use it with the laptop screen. If you just want to use the external monitor, a trick I use is: turn on the laptop with the monitor connected, then close the lid before the PC boots. It will detect the external monitor and because the lid is shut, will use it as the main and only display. Or get a docking station to help with that.

http://answers.microsoft.com/en-us/windows/forum/windows_7-desktop/how-to-set-primary-monitor-in-extended-desktop/e9aaef4e-1dc7-4139-9b4a-f5b562d4fd27