The webpage you pointed to in your question clearly says 'un-install your current version'. So it would best to get rid of the very old V19 version and go for the latest version of 2D Drafting.
The webpage in your post is the right place to begin.
Thank you for the Aug 7 e-mail Subjectid you get the answer you needed?
I replied to Tushar at 'email@example.com' on July 31with my clarifying information.
So I have not received the answer I need to install version 4 on Vista.
Thanks, Kushar for your message yesterday.
The current version was un-installed previously.
Solid Edge ST6 does not install on my Windows Vista Home Premium 32 bit system.
Since Solid Edge V19 program and its license are gone and Solid Edge ST6 does not install on Windows Vista, I saw from the options on webpage titled Solid Edge Free 2D - Thanks for Registering that I needed to ask you for an earlier version that supports Windows Vista Home Premium 32 bit system.