I am guessing this is an FAQ somewhere but the question came up on the alias today. 

We have a BVT which runs on the BVTServer. We tested BVT remotely from different machines through VS and it is working fine from all the machines.

But when we start the Build from Build Server we get the following message in the log and build just hangs:

“Starting execution…”

If we run BVT from Build Server directly through VS it works fine.

Almost certainly the issue is one of the tests being run during the build is popping up a Window.  To find the Window that is getting opened connect to the console session on the build machine using the service account.

The directions for doing this can be found at:

How to Connect to and Shadow the Console Session with Windows Server 2003 Terminal Services

http://support.microsoft.com/kb/278845