Configuring IIS to Run 32-bit Applications on 64-bit Windows (IIS 6.0)

Conditions:
Operating system : 64 bit
Web Application : 32 bit
Probable errors : Could not load assembly

When running any application on IIS and the dll cannot be loaded,
it could be that the application is a pure 32 bit application and the operating system is 64bit

You would need to enable 32 bit applications in IIS

Following is the process explained:
Configuring IIS to Run 32-bit Applications on 64-bit Windows (IIS 6.0)