Subscribing has nothing to do with the Copy Protection or Registration of a piece of software.
Off-the-shelf software has an internal licensing system. If you install software on a device, it does a check to see if you have permission to install it, otherwise it doesn't work. It also registers you as a user with the company that created the software. In return for this your software automatically updates and maintains itself.
For example, you buy a Browse 3 software. By default, it is licensed for one user. The first device you install it on, no problem. The moment you try to use the software on a second device, it will refuse to work and probably ask that you purchase another license.
The exact mechanism for this copy protection "check" is left abstract. You can, however, disable this check by cracking and modifying the software. At the same time you probably will want to remove the Registration function so the guys who wrote the software can't track you.
The problem now is that the cracked software can no longer "call home" to request patches and updates. So it's rating degrades over time as it falls behind the "state of the art" and becomes slowly obsolete. To fix this, you need to patch and update the software manually, which means regular programming tests to perform the maintenance.
You can install the software on just one commlink and just run it there, accessing that first commlink from other commlinks. That works. Like installing software on your computer at work and accessing the software remotely via VPN from a terminal at home. But you still have problems with Registration, which most Shadowrunners don't like. Something about the Corps being able to track you with it, I dunno.

-k