As many people don't know, in Windows certificates can be bound to ports for securing content transferred over those ports. IIS happens to be particularly negatively affected by this if another program has a certificate bound to a port that you want to use, e.g. 443 for serving web pages.
Use the information at the following page to find the certificate binding and delete it :
The short version:
Find the port: netsh http show sslcert | grep -C 5 443
This command will show all the SSL certificates that are bound to ports on your machine.
Delete the port: netsh http delete sslcert ipport=0.0.0.0:443
This should help deal with some of the more annoying (and less verbose) errors when doing things like trying to configure WCF services to use SSL.