Unable to copy file reference.dll to bin/reference.dll. The process cannot access the file reference.dll because it is being used by another process

Question

For one of my ASP.NET 3.5 applications, every single time I try to build the web app, it throws the following build errors in Visual Studio 2008:

Error 16

Answer 1

I was using Visual Studio 2012 when this started happening on a 7 year old solution (for the second or third time: I've been to this question before).

I tried the various voodoo. I cleaned the solution. Didn't work. I restarted Visual Studio. Didn't work. I was confident that last one would work, because that is the voodoo that worked last time.

Ultimately, I remembered a security update had installed last night and was configured when I started my machine this morning - (Connected or not? No Idea) - So, I restarted Windows, and voila, it all worked like magic again.

Thanks MS for more mind mincing.