Updating operating system on mac
To get mac OS High Sierra on your Mac you need to do the following: Luckily the download happens in the background, so you can continue to work or surf the web.
Once the installer has downloaded you are ready to install the mac OS software on your Mac.
Apple suggests that you should have 8GB of free space on your Mac's drive before you install a major mac OS update, but we recommend aiming for 15GB to 20GB.
The Yosemite installer was 5.16GB, for example, and you'll need to allow some room for temporary files.
Apple issues a major update to its Mac operating system once a year, previewing it at WWDC in June, and issuing the final version in September, usually.
However, updates continue to be released throughout the year, often because Apple needs to address vulnerabilities or fix problems, but sometimes to add new features, such as new Emoji.
If you have less than 4GB RAM it is definately time to consider upgrading to a new Mac, or installing more RAM – if you decide to do that, make sure that the RAM you choose is compatible. You may be concerned that you have some software that you need to use that may not work in the new operating system - the apps in Microsoft Office 2011 won't work, for example!
Some people will be able to test the beta out on their Macs.
Both tests check your Mac for other hardware issues, such as bad RAM.
Read more about using Disk Repair to fix a Mac here.
Boot into recovery mode (by holding down Command R at startup) and use Disk Utility from there to perform the recommended repairs.
You can also run the Apple Hardware Test (for Macs older than June 2013) or Apple Diagnostics (for Macs from June 2013 or later).