LoadTest Controller

I was in the process of exploring Controller and Agent for Load testing using VSTS 2008. I am facing an issue in the same

"Failed to connect to remote Controller on machine 'tfs_Server', port '6901': No connection could be made because the target machine actively refused it ."

In the process of troubleshooting the problem, I read in one of theblogs is to install Visual Studio 2008 SPI in all the machines involved. i.e Controller, Agent and Client

In my scenario my Controller and TFS Server was the same machine.
I installed it on all machine but after I installed it on my controller machine, I was then not able to connect to my TFS Server from any of my clients.
I got the error below on all my client machines

"TF31001: Team Foundation cannot retrieve the list of team projects from Team Foundation Server tfserver. The Team Foundation Server returned the following error: Team Foundation services are not available from the server.
Technical information (for administrator):
TF30059: Fatal error while initializing web service. "

Then I unstalled the SPI from the machine and then was able to successfully connect to the TFS Server

One more problem I faced then was I was getting error as below when I run my Load test.

"No connection could be made because the target machine actively refused it "
On going to the Controller machine and checking the services, the service for the controller was stopped. I tried to start the service manually but then the service stopped by itself giving me a message.

"The Visual Studio Team Test Controller Service on Local Computer started and then stopped. Some services stop automatically if they have no work to do, for example, the Performance Logs and Alerts service. "

Then I realised that the whole problem was caused because my controller was a 90 Day or 25 Test Run trial.