After updating to Internet Explorer 10, I started receiving the error when debugging with Visual Studio 2010:
"Attaching the Script debugger to process [####] iexplore.exe failed. Another debugger may already be attached to the process."
- Close all instances of Internet Explorer. (I will add you can leave Visual Studio open)
- Run a command prompt as Administrator and paste this little gem into the command line:
It worked like a champ for me (and apparently others from comments on the stackoverflow post.)
Good riddance to an annoying message! Happy coding.