Calling LoadLibraryEx on ISAPI filter "C:\windows\Microsoft.NET\Framework\v4.0.30319\\aspnet_filter.dll" failed

Ok, this was again a really tricky one. Tried to find the answers but none worked. Below is given the error message that is displayed on any webpage (e.g. http://localhost/)

HTTP Error 500.0 - Internal Server Error

Calling LoadLibraryEx on ISAPI filter "C:\windows\Microsoft.NET\Framework\v4.0.30319\\aspnet_filter.dll" failed

Looking at the event log this is what I saw:

ISAPI Filter 'C:\windows\Microsoft.NET\Framework\v4.0.30319\\aspnet_filter.dll' could not be loaded due to a configuration problem. The current configuration only supports loading images built for a AMD64 processor architecture. The data field contains the error number. To learn more about this issue, including how to troubleshooting this kind of processor architecture mismatch error, see http://go.microsoft.com/fwlink/?LinkId=29349.

And that totally zapped me for a second or two. The error is saying that somehow the current configuration is supporting the AMD chipset !!!! How can that be ???

Anyways, for me re-registering IIS (aspnet_regiis –i) dis not work. The following are the steps that did work.

1. Control Panel > Programs and Features > View Installed Updates
2. I uninstalled anything and every update that had to do with .Net 4.0. (How did I know this ? Because I knew the date on which I installed the updates was the day before which I did not have this problem. So I inferred that those updates should be the ones causing trouble.) Here is the list of updates I un-installed (there might be a couple that are not listed, however, I un-installed everything that had to do with .Net 4.0)
• KB2478663
• KB2473228
• KB2468871
• KB2446708
• KB2160841
• KB2468871
3. Reinstalled .Net 4.0 from this location.

This fixed the issue for me.