We installed CF 11 Standard 32 bit on a Win 2012 R2 server with IIS 8.5. We tried installing both with 32 bit "Enabled = False" and "Enabled = True". Both resulted in Error 500 or 500.19.
Below are more details, with images following for the errors and the Handler Mappings.
The CF11 HKLM software key is under the WOW6432Node key. We get the 500.0 error when the DefaultAppPool 32.bit setting is "false" and a Test.htm program works just fine. If we enable 32-bit, the result is a 500.19 error for both the CF admin and the Test.htm.