Hi,
Thank you for writing to Microsoft Community Forums.
I understand that you receive an error, ‘please remove the current cd-rom and insert cd-rom number2’ when trying to install catia v5 r20 software on your computer.
As per the error message, it seems that the files required for the installation of software are missing or incomplete. You may want to try downloading the software again and check if the installation goes through.
However, it is always recommended to download the software from the software developers website, so that you get a genuine and complete software.
Regards,
Nikhar Khare
Microsoft Community - Moderator