If you want to record windows screen, you can upgrade your computer to windows 10, and then you can use the default recording feature to record screen on windows.
If you are using Mac, you can use Quicktime to record screen on Mac.
Another alternative to record screen on both windows and mac is to use FoneLab screen recorder.
It is a powerful tool for users to record screen, capture audio, record webcam video, and take screenshots accrording to your needs.
You can download and have a try now!