HC Website Giving Error: Server Error In Application

Question: I am getting the following error after HC installation on server:

Server Error in '/' Application.
Retrieving the COM class factory for component with CLSID {F9DE199F-958B-4EA2-8031-1147D569B9EE} failed due to the following error: 80040154.

When you try to run HC website on x64 machine in which IIS is running in x86 (32bit ) mode then such error appears. 

The resolution to above problem is to run IIS in 64 bit mode using the instructions below:

ASP.NET 2.0, 64-bit version

To run the 64-bit version of ASP.NET 2.0, follow these steps:
  1. Click Start, click Run, type cmd, and then click OK.
  2. Type the following command to disable the 32-bit mode:
    cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET W3SVC/AppPools/Enable32bitAppOnWin64 0
  3. Type the following command to install the version of ASP.NET 2.0 and to install the script maps at the IIS root and under:
    %SYSTEMROOT%\Microsoft.NET\Framework64\v2.0.50727\aspnet_regiis.exe -i

Note: For more detail read Microsoft Article

Precautions: The web applications which typically require 32 bit mode of IIS may stop working after running the above commands.