I recently encountered an issue where users attempting to connect to a server via the “Remote Desktop” tab in the RD Web Access site were presented with a “Remote Desktop can’t find the computer” error when attempting to connect to a resource, as shown in the below screenshot.
After performing some research it appeared that the DefaultTSGateway property in the RD Web Access IIS site needed to be populated with the external fully qualified domain name of the RD Gateway server. By performing this, the request made for a server via the Remote Desktop tab in the RD Web Access site was then directed through the RD Gateway server. To achieve this, and resolve the issue the following actions were performed.
1. Connect to your RD Web Access server and open the IIS 7 management console.
2. Expand Server Name -> Sites -> Default Web Site -> RDWeb -> Pages -> en-US
3. In the Application Settings pane, click the DefaultTSGateway entry and select edit from the action pane on the right hand side, as shown in the below screenshot.
4. In the edit DefaultTSGateway box that is now presented, in the value section, enter the external fully qualified domain name of your RD Gateway server. For example, rdsgateway.domain.co.uk and click ok.
5. Test resource access from the RD Web Access site to a server via the Remote Desktop tab. You should now be able to connect and authenticate correctly. One thing to note is that you will only be allowed to connect to internal resources that have been specified in your Resource Authorisation Policy (RAP) in the RD Gateway manager.
That’s it, your all done.