server 2008 .net framework 4 503 error

Question

I just installed .net 4 on my server 2008 and I keep getting Service Unavailable

HTTP Error 503. The service is unavailable.

messages from any application I try to run as .net 4. The application pool keeps stopping. Event view shows: "The worker process failed to pre-load .Net Runtime version v4.0.30319."

Answer 1

Problem has been solved. I uninstalled .net 4 and reinstalled using the "web platform installer". restarted and now it works.