What does “Register for COM Interop” actually do? Q2

Question

What exactly does the VS project option "Register for COM interop" actually do? Because when I build my library with this option enabled I'm able to view it in the COM tab inside the VS Add Reference screen. But if I build without this and then run regasm manually (already including /codebase parameter) I can't see it in the COM Dll list, neither inside VS Add Reference screen or VB6 References screen. So, I'm wondering -- what does VS2010 do that I'm not doing?

I already searched for this topic inside StackOverflow, and found this link, which didn't solve my problem: What does "Register for COM Interop" actually do?

Regasm shows me: Types registered successfully So, I don't have any extra info.

Answer 1

Visual Studio enumerate the HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Classes\TypeLib registry key to fill the COM tab. Drop Wow6432Node if you use the 32-bit version of Windows.

So what's missing is that you forgot to ask Regasm.exe to register the type library. You need to also use the /tlb option.