I am trying to deactivate my Flash Builder 4.5 (on 2 machines) so that I can activate on 2 other machines. I called installation support and they directed me here.

I’m reasonably sure you’re simply out of luck here.

The final version of the program came out in 2012 at version 4.7. Main support ended in 2017 and all extended support ended in 2019.

Just in case you were still developing for it, Flash Player itself ended all support in 2020 and all Flash content has been blocked since 2021.

I’m pretty sure, like the vast majority of Adobe programs from before the Creative Cloud subscription service, the licensing servers have been deactivated and there is no way to deactivate or activate the program.

Also, it may be that it is not an issue with deactivating but an issue with a 4.5 license key needing a 4.0 license key.  I primary issue is that I can’t activate on my new machine.