See the question and my original answer on StackOverflow

Regasm doesn't come with Visual Studio, but with the .NET Framework itself. So you can find it in paths like


to register your dll in the 32-bit part of the registry and


to register your dll in the 64-bit part of the registry.

If you build your dll as "Any Cpu", you can register it for both 32 and 64 bit part of the registry.