ITSU
 

How can you tell what version of Mac OS you are running?

This can easily be done by going to the "Apple Menu" and clicking "About This Computer" for OS 8.x - 9.x or "About This Mac" for OS 10.x. Knowing what version of the OS is very important in troubleshooting computer software and hardware problems. It will help you determine which drivers you need to install on the computer for things like scanners, printers, etc. Below are examples from the different versions of Mac OS:
Mac OS 9.2:
apple9
about9

Mac OS 10.1:
apple
about