Is it possible to disable the auto-merge option in Visual Studio Team System 2008? If so how?

Solution 1:

Try do the following (working in all Visual Studio versions from 2012-onwards):

Tools -> Options -> Source Control -> Visual Studio Team Foundation Server -> Uncheck "Attempt to automatically resolve conflicts when they are generated":

enter image description here

Solution 2:

The short answer as of Visual Studio 2008 seems to be no.