Not enough memory. Close your other programs, and then try connecting again. If the problem continues, restart your computer, and then try connecting again. If you still cannot connect, contact your network administrator or technical support.

Network failure. Make sure that your router is turned on (home networks only), the Ethernet cable is plugged into your network adapter (wired networks only), your computer's wireless switch is turned on (mobile computers on wireless networks only), and your network adapter is working. If the problem continues, contact your network administrator or the person who set up your network.

The remote computer cannot be found. Ask the administrator of the remote computer to verify the computer name, and make sure you typed the name correctly. If you still cannot connect, try typing the IP address of the remote computer instead.

Connecting a home computer to a computer on a corporate domain requires an intermediate step to ensure that the computers can communicate. One way to do this is to establish a virtual private network (VPN) connection to the corporate network. Another way is to use a Terminal Services Gateway server. If you have problems doing either of these things, contact your system administrator or technical support.

Connecting two home computers across the Internet is also possible. However, doing this typically requires detailed knowledge of the router configuration, port mappings, and IP addresses.

If authentication is enabled, you must type a full computer name (for example, Computer1.Example.com) on the General tab of the Remote Desktop Connection dialog box.

To find out what level of authentication is enabled:

1. From the Windows Vista default Start menu, point to All Programs, Accessories, and then click Remote Desktop Connection.

2. In the Remote Desktop Connection dialog box, click Options, and then click the Advanced tab.

3. The full computer name is listed under Computer name, domain, and workgroup settings.

1. From the Windows Vista default Start menu, right-click Computer, and then select Properties.

2. The full computer name is listed under Computer name, domain, and workgroup settings.

• The Remote Desktop port might be blocked by a firewall.

  If you are using Windows Firewall, use the following steps.

  1. From the Windows Vista default Start menu, click Control Panel.

  2. In Control Panel, click Security.
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  3. In the Control Panel Security window, click Windows Firewall.
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  4. In the Windows Firewall window, click Allow a program through Windows Firewall. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
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  5. Click to select the Remote Desktop check box.
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  6. If you are using a different firewall, make sure the port for Remote Desktop (usually 3389) is open.

• Remote connections might not be enabled on the remote computer. To fix this:
  1. On the remote computer, from the Windows Vista default Start menu, click Control Panel.

  2. In Control Panel, click System and Maintenance, and then click System.

  3. In the left pane, click Remote Settings. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

  4. Under Remote Desktop, click either Allow connections from computers running any version of Remote Desktop or Allow connections only from computers running Remote Desktop with Network Level Authentication.

  5. Click OK.

• The remote computer might be too busy to accept any more connections right now. Wait a while, and then try connecting again.

Note: This information provided by Microsoft.