If you need a truly free option, TuxGuitar is the best answer. It is an open-source, completely free alternative that can open and edit .gp files (the Guitar Pro format). It doesn't look as modern and the sound engine isn't quite as polished, but it is 100% functional and safe.
: If you have already purchased a license, you can activate it on up to 5 computers simultaneously. You can retrieve your key at any time by logging into your account on the Guitar Pro website . guitar pro 7 license key free