Hi Naomi,

>Because there are .NET 3.0 and .NET 3.5

3.0 and 3.5 are Framework versions. REGASM is linked to the Runtime version. The CLR fortunately only exists in three versions: 1.0, 1.1 and 2.0. The Framework versions 2.0, 3.0 and 3.5 all base on the 2.0 runtime.

The tool needs to be registered with the version of the runtime with which it was compiled. Even if Microsoft would release a new version of the runtime, this wouldn't affect the existing program as it still needs the 2.0 runtime.