NUNIT + VS2010 = Unable to copy file from /obj to /bin...being used by another process

I am trying to run some unit tests开发者_Python百科 using NUnit while I have the project open, and VS 2010 cannot rebuild the project while the assembly is loaded in NUnit. I have looked around and haven't found any solutions that seen to fix it. I can close NUnit, then the project builds fine. This is a the same solution based on Rob Conery's BDD demo found here: http://tekpub.com/view/concepts/5

Any thoughts?

Turn ON the windows process "Volume Shadow Copy" as specified in this question. The question is a year old, but it worked for me with VS2010 and NUnit 2.5.5. There is also a second answer in that question but it didn't work in my scenario.