Recently I was trying to host a website that is building on top of .net 4.0 into my IIS 7.X server. The framework installed and configured correctly but the site was not being able to show up. The main problem was the app pool turning OFF whenever I was trying to send request to the website. That was a very strange thing for me.
I checked the event log and I found the IIS is logged the following error message into my Event log
“The Module DLL C:\Windows\system32\inetsrv\rewrite.dll failed to load. The data is the error.”
After research and investigation on why this error message showing up I found the “Rewrite.dll” is missing thus I need to install it.. This dll supposed to be found on the following path “C:\Windows\System32\inetsrv”
To install it, you need to download on of the installed (based on you OS archi) and install it.
I hope this would help you fixing the issue that you are looking to fix.