Command copy exited with code 4 when building - Visual Studio restart solves it

Question

Every now and then when I build my solution here (with 7 projects in it) I get the dreaded \'Command copy exited with code 4\' error, in Visual Studio 2010 Premium ed.

Answer 1

I crossed the same error, but it is not due to the file is locked, but the file is missing.

The reason why VS tried to copy an not existing file, is because of the Post-build event command.

After I cleared that, problem solved.

UPDATE:

As @rhughes commented:

The real issue is how to get the command here to work, rather than to remove it.

and he is absolutely right.