I get the above message in my task list when I try to compile my solution.

The file is called interface.dll

Here's the steps I take.

run iisreset from cmd.
then manually start and stop IIS. reboot PC.

I then delete ALL instances on this DLL off my PC.
I then toast all temp .NET files.

I then load solution A, which is the main solution that uses interface.dll
I then build all of solution A's projects.
I then close down .NET.

I then open solution B in .net
Try to compile and straight away I get the error in the task list.

What on earth is locking it???!!!

I haven't run any apps that use this DLL

Woka