Ahh ok
Well firstly you'll have to download some software so that you can use it, which i think is the easiest way to do it
But you need to configure your computer to allow it to accept remote desktop connections
Steps to allow other computers for a remote desktop connection
To set up this computer to use Remote Desktop:
Open System in Control Panel.
On the Remote tab, select the Allow users to connect remotely to this computer check box.
Ensure that you have the proper permissions to connect to your computer remotely, and click OK. You must be an administrator or a member of the Remote Desktop Users group on your computer. For more information, see To allow other users to connect to your computer.
Notes
You must be logged on as an administrator or a member of the Administrators group to enable the Remote Desktop feature.
To open a Control Panel item, click Start, click Control Panel, and then double-click the appropriate icon.
To use Remote Desktop, you need the following:
A computer running Windows XP Professional ("remote" computer) with a connection to a Local Area Network or the Internet.
A second computer ("home" computer) with access to the Local Area Network via network connection, modem, or Virtual Private Network (VPN) connection. This computer must have Remote Desktop Connection, formerly called the Terminal Services client, installed.
Appropriate user accounts and permissions.