Laptops
typically come with a place in the back to connect an external monitor.

The majority of new laptops support dual screen when used with Windows 98 / ME or XP. Windows2000 does not support dual screen on laptops. To check if your laptop is dual screen compatible plug a projector or a secondary monitor into the laptop’s monitor port. From the Windows desktop right-click and select 'Properties.' A dialog box will appear. Select the 'Settings' tab and you will be shown the monitor properties.
If two monitors are shown here, simply click on the second monitor and check the 'Extend desktop to this monitor' option. Press OK and dual screen will be enabled.
If there is no second monitor shown, then click the 'Advanced' button and try to locate an option that is related to multiple monitor output. Locate the option and make the secondary display separate to the primary. Restart your Computer you should see the second monitor on the ‘Settings’ tab.