I've been looking around on this problem and whilst I've found a few "solutions" it seems that a lot of these "solutions" are stumbled upon or cannot adequtely explain what really worked.
I've tried a number of the solutions but I'm still having issues.
I've created a .PFX within Visual Studio. TeamCity and the Build Agent are all on my local development machine so there isn't any other PC involved in my situation.
When TeamCity tries to build this project I get an error:
error MSB3325: Cannot import the following key file: name.pfx. The key file may be password protected. To correct this, try to import the certificate again or manually install the certificate to the Strong Name CSP with the following key container name: VS_KEY_6E76201C7E991E97
Everything is running under Local System Account both Team City Server and the TeamCity Build Agent.
So where do I install the certificate? I've opened MMC.exe and imported it into a number of "obvious places" such as the Local Computer Certificate Snap-In. I tried importing it into the Personal and Trusted CA roots but neither of those worked.
So where on earth do you put it?