There are six steps you'll need to follow to set this up. Each one is explained in detail below.
1. Allow remote connections to the computer you want to access.
2. Make sure Remote Desktop is able to communicate through your firewall.
3. Find the IP address of the computer on your home network that you want to connect to.
4. Open your router's configuration screen and forward TCP port 3389 to the destination computer's IP address.
5. Find your router's public IP address so that Remote Desktop can find it on the Internet.
6. Open Remote Desktop Connection and connect.
Allow remote connections to the computer you want to access
To access one computer from another computer, you first need to allow remote connections on the computer you want to access, which must be running one of the following versions of Windows:
Windows XP Professional edition
Windows Vista Business, Ultimate, or Enterprise edition
Windows 7 Professional, Ultimate, or Enterprise edition
On the computer you want to access, follow these steps:
Open System by clicking the Start button Picture of the Start button, right-clicking Computer, and then clicking Properties.
In the left pane, click Remote settings. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
Under Remote Desktop, select one of the options to allow connections. For more information about these options, see What types of Remote Desktop connections should I allow?
Click Select Users.
In the Remote Desktop Users dialog box, click Add.
In the Select Users or Groups dialog box, do one or more of the following:
To specify the search location, click Locations.
To specify the types of objects (user names) that you want to search for, click Object Types.
In the Enter the object names to select box, type the user name that you want to search for, and then click Check Names. If the user name isn't found, click Advanced to run an advanced search.
When you find the correct name, click OK.
The name will be displayed in the list of users in the Remote Desktop Users dialog box.
Click OK, and then click OK again.