ASP2ASPX creates the matching .NET assembly for ActiveX/COM automatically during converting ASP to ASP.NET.
The ActiveX/COM DLL must be registered on your computer. If the AcitveX/COM is not registered by 'regsvr32', ASP2ASPX will report error message 'Invalid ProgID: xxx.xxx' in \logs\asp2aspx.htm file.
You also can create the .NET assembly with TLBIMP.exe manually. Then put the assembly in [ASP2ASPX]\com\ directory.