Now this problem is solved.
By using .Net framework cleanup tool.
I have uninstall .net framework 4.0 then re-install it.
Also I have read articles for this error each article gives some useful suggestion so it helps a lot to understand the problem and how to solve it.
http://mvolo.com/troubleshoot-iis7-errors-like-a-pro
This link is very much useful for above error.