If 2 hours isn't enough, you can earn longer license keys for free by contributing to the Keyran community. This is a legitimate way to "pay" for the software with your time rather than money.
This is what most people mean by "free license key." These keys are obtained from: keyran license key free better
If you are a serious gamer, the paid version is technically "better" because: If 2 hours isn't enough, you can earn