How do I disable the Performance Explorer from opening every time?

This is actually BUG since Visual Studio 2012 that's been open since summer 2012 with still no official MS fix.

Here's a workaround to this annoyance:

1. From Windows explorer, go under your VS project folder
2. Remove the following file types if present:
   • file.vsp - (VS Performance Report)
   • file.vsps - (VS Analyzed Reports)
   • file.psess - (VS Performance Session)
3. Re-open the Solution, if error, click OK (the Solution will still load)
4. Close the solution
5. Re-open the solution - the Performance Explorer tab will be finally gone!
   

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   @B. Clay Shannon - thanks for update to also delete *.vsps

In VS2015 Update 1 deleting the .psess file as per Leonel Gurdian's answer doesn't seem to work. Changing true to false in the following part of the .sln file did the trick though.

GlobalSection(Performance) = preSolution
    HasPerformanceSessions = true
EndGlobalSection

And it is still there in VS 2015 RC! You have to chose more options to start Performance Explorer but if it's once opened, it comes again each time you start IDE atleast when you open your project.

But deleting the psess-file in ProjectFolder still works.