[@Mick] That’s the norm with giveaway software. Most of the free software I’ve got from places like this and bitsdujour.com have to be activated on the day of the giveaway. The software will either work forever or will have a period it will work (usually a year, can be as low as one month). You don’t get free upgrades to new versions, and often, not even to incremental versions of the software. So, with some of these, if you have version 5.6 and 5.7 is released, and if you install 5.7 over 5.6, it won’t activate with your key.
Some of these will allow you to reinstall (like after a hard drive crash, or moving to a new computer), but only for that same version that you originally registered the software for.