If I have an HPC with a USB key for 2.5 or 3.x can I download the 4.x and it works or do I have to buy the upgrade with the HASP key.
Version 4.X and higher do not validate runtime against the Crypkey based products. You do not have a license to run Version 4.0 in this scenario so you must purchase an INTX-7140 upgrade in order to run Version 4.0 on this HPC unit.
If I have a PC running InteractX runtime and using a USB key will it still work with 4.x (runtime / development)
It will still work with the version under which it was purchased and licensed. In order to upgrade to version 4.0 the user must purchase an upgrade.
Can I upgrade an old 1.91 unit?
Yes - but you must purchase the upgrade in two steps with the appropriate INTX- 7xxx part #'s for both 1.x to 3.x upgrade (development or runtime) and for the 3.x to 4.x upgrades.
If there a license upgrade that does not have a key?
NO - All upgrade part#'s include a key.