Do you want to test, if WinSCP is installed or registered?
If registered, IMHO the best test, is to try to instantiate the WinSCP.Session class.

Hi,
I am developing an MS Access 2010 app in VBA
I am trying to check if WinSCP is installed on a machine.
As WinSCP.tlb is a reference to my project,

I am checking via VBA, if the file "%windir%\system32\winscp.tlb"
(or "%windir%\system64\winscp.tlb") exists

If not, I am registering COM assembly via code, with RegAsm.exe using:
%WINDIR%\Microsoft.NET\Framework\<version>\RegAsm.exe WinSCPnet.dll /codebase /tlb

Is it possible to read WinSCP registry key and value for that?

I can read registry keys and values in VBA