Consume a .NET Assembly from a classic ASP page. by Darren Neimke

All I would add is that RegAsm lives in:

C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322

NB
Beware of parameterized constructors, i.e. defining a Sub New() with parameters, if you do this your class will not be eligible for COM registration and won't show up in the registry or be creatable from your ASP pages / VB components.