I have had so many people at work coming to me with this issue. So, think it is worth making note of it here.
Problem: Visual Studio 2005 - when you try to run any application pops up this window with a message - "debug handle is invalid".
The fix is to get your "Terminal Services" running.
Start -> Type Run -> type services.msc and hit enter ->
Look for the the Terminal Service -> Right click that and Start.
Probably you could make it Automatic to start every time you boot up.
VS 2005 hooks up with this service to run its debugger session.