I just remember the Stardock way of selling updates - my licensed WindowBlinds version just didn’t work anymore when Windows Vista or 7 (too long ago to really remember which Windows it was) was out, and would not, so I needed to buy an upgrade in order to use it on my computer again. Even though it wasn’t called that way, it was some kind of subscription that terminated inexpectedly, so I had to renew.
I have to come to Stardock's defense here, because as a software developer I feel the same way as they do concerning this issue:
A change to a new version of Windows is not a trivial thing, especially when talking about applications that work so close to the OS itself as Windows customization applications do. A lot of the time they depend on specific Windows functionality that Microsoft can - and often does - change.
Same thing happens with hardware drivers, for instance. How many times did you have to wait for an updated driver to be released in order to use hardware that was working fine with the previous Windows version? And sometimes hardware vendors don't even bother making new drivers, leaving you with a costly paper weight that would otherwise be fully functional. Now THAT is infuriating.
Bottom line is, when you upgrade to a new version of Windows you should NOT expect things to keep on working as before - some will, some won't. You know you run that risk whenever YOU make the decision to move to a new Windows version. And nobody forces you to upgrade Windows either, certainly not the software nor the hardware vendors. Their stuff was working properly when you bought it, on the version of Windows it was intended for.
When a new Windows version comes out, making your software work on an environment that is sometimes radically different from the one before is not a trivial task either. It implies many hours of research to figure out what Microsoft changed and how to work around it. It's a lot of hard work.
I remember when Vista came out, for instance. It was so radically different from XP under the hood that I literally spent months working on getting Winstep software ready for it, all the time sweating and cursing under my breath.
This amount of work and effort deserves to be rewarded, so you can't blame the software vendor if he decides to charge you for it. It was YOUR decision to jump to a new Windows version, after all.
Now, as you know, there are several types of upgrading policies out there: some vendors charge you for MAJOR versions (which is pretty arbitrary: I can change a couple of lines of code, make a few cosmetic changes, and call that a major version upgrade if I need to 
) and Stardock and Winstep have a one year of free upgrades policy (with renewals costing a fraction of the initial purchase price).
If your year of free upgrades has already run out when you install the new Windows version, you can't then blame the vendor if software that was made for the previous version of Windows no longer works correctly. You have a choice of paying for an upgrade whenever one is released, stop using the software, or go back to the previous version of Windows.
The other side of the coin of the 'one year of free upgrades' policy is that you won't have to pay a dime if the update making the software compatible with the new Windows is released while your period of free updates is still in effect. 
