I’m installing a ColdFusion application and ran into a few issues. Here, mostly for my future reference, is the process of solving those problems.
ColdFusion was installed before IIS 7. As such, IIS didn’t have the correct handlers for ColdFusion files. Follow the instructions on Codecurry to get that resolved. The post is dated (the screenshots are on Vista), but the general process is still correct. Make sure these IIS features get installed: ASP.NET, .NET Extensibility, CGI, ISAPI Filters, and ISAPI Extensions. Then run the ColdFusion Web Server Configuration Tool to perform the necessary IIS configuration.
Once that was working, I started getting HTTP 500 errors. In my case, ColdFusion was only set up to run in 32-bit mode, even though IIS and Windows Server 2008 R2 is 64-bit. To fix this, go into IIS Manager and select the Application Pool your website is using. Choose Advanced Settings and change Enable 32-Bit Applications to True. (If you prefer the command line, see these instructions for this change.)