Hello,
Thanks for reaching out to us!
Unfortunately, we do not allow to try multiple free-evaluations on the same PC. It’s limited to only one machine. You can try to download the installer file on another PC and it should work fine.
Also, If you need OptiSystem for longer duration to complete your project, then I urge you to lease the license (for 1 year) or apply for the student license, which are at subsidized rates. Let me know if you need further assistance with it?
I hope this was helpful?
Warm Regards,
Saurabh Bedi.