Common Error Messages

“Your computer can’t connect to the remote computer because an error occured on the remote computer that you wanted to connect to. Contact your network administrator.”

“This computer can’t connect to the remote computer because the certificate authority that generated the Terminal Services Gateway server’s certificate is not valid. Contact your network administrator.”

“Remote Desktop cannot connect to the remote computer because the authentication certificate received from the remote computer is expired or invalid. In some cases, this might also be caused by a large time discrepancy between the client and server computers.”

Error occured on the remote computer

RD or TS Gateway certificate error

Remote computer certificate expired or invalid

RDP client version upgrade

Our virtual labs use an RDP connection through a TS-Gateway server. For this type of connection you will need a remote desktop client v6.0 or later.

To verify which version of Remote Desktop client you have, open remote desktop (Typically Start -> Programs -> Accessories -> Remote Desktop Connection), click the small icon in the top left corner of the window, and pick About. You should see a window similar to the one shown below:

The important information is circled in the window shown above. Older versions of the Remote Destop client may not show the version. Control Version 6.0 and later is required. If you do not have a supported remote desktop client already installed, one is available from the Microsoft site:

  • For systems with Windows XP SP2 install the Terminal Services 6.0 client from
  • For systems with Windows XP SP3 install the Remote Desktop Connection (RDC) 7.0 client from There is a known issue with the RDC 7.0 client and SP3. You may receive an error message when attempting to connect. This error can safely be ignored and you should be able to connect if you retry.
    If you wish to eliminate the errors entirely, you will need to enable Network Level Authentication (NLA) which has been disabled in SP3. This involves editing the windows registry which is not recommended. Follow the steps under How to turn On CredSSP from
  • For systems with Windows Vista the Remote Desktop Connection (RDC) 6.0 is already installed. You can optionally upgrade to the RDC 7.0 provided you have Vista SP1 or later. You can install from
  • For systems running Windows 7, no upgrade is necessary.