Sometimes, you will get the following error after deploying your web application (developed for 64 bit environment and if you referred to any GAC DLL in your application) on IIS 6 or IIS7.
Could not find the path of
C:\Windows\assembly\GAC_MSIL_<Dll Name>_<GAC ID>\Bin
This error occurs because of your IIS currently not supporting 64bit applications, so you need to enable the 64bit compatibility on IIS and you can resolve this by using the following steps on different IIS versions based your requirements.
Step 1: Click Start, click Run, type cmd, and then click OK.
Step 2: Type the following command to disable the 32-bit mode:
cscript %SYSTEMDRIVE%\inetpub\adminscripts\adsutil.vbs SET
Step 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:
Step 4: Make sure that the status of ASP.NET version 2.0.50727 is set
to Allowed in the Web service extension list in Internet
Information Services Manager(if your application deployed on
windows 2003 or 2008).
Step 1: Open the Internet Information Service Manager
from Start Menu or Control Panel --> Administrative
Step 2: Expand the Application Pools Node then find your Website
Application Pool then right click on it then click on
Advanced Settings, it will popup the settings screen here you
need to set false for Enable32bitApplication.This settings may
affect your existing 32bit application,if you get any error on
your 32 applications then you reset the above setting and
create a new application pool just like existing on and use it
for 64bit with appropriate Enable32bitApplication setting
(value must be false).