Checking for Framework Installs

How can a program check whether WCF is installed?

The installation status of WCF can be quickly checked by looking for the registry keys put in place by the installer. Take a look at the values under the key:

HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Setup\Windows Communication Foundation

These include the DWORD InstallSuccess (should be equal to 1) as well as the version and installation paths of the installed copy.

For other installation checks, take a look at Aaron Stebner's sample programs for testing the registry for framework installations. There's a slightly simpler version that only uses the registry and a slightly more complex version that also uses mscoree.dll.