Need Rhinoceros Version 4.0 SR4b download link?

Hello,

I had bought Rhinoceros Version 4.0 SR4b and now lost our CD. I want to install it in another computer. How do I go about it?

Also, Is it possible to use 1 license key on two computers?

Assuming that you registered your license, contact McNeel directly at sales@McNeel.com

Yes, you can install it on all the computers that are owned by you but you can only run it on one machine at a time.