How can I check which version of the Mac operating system my computer is running?

This discussion has a more recent version.

Knowing the Mac operating system version can help you determine whether your Mac computer is up to date or meets the system requirements of your F-Secure product.

  1. Go to the Apple menu on the top-left corner of the screen.
  2. Select About this Mac.
The version of the operating system is displayed on the screen that opens.