Apple announced OSX 10.10 or Yosemite at the WWDC 2014 and promised to release the Beta Preview of the latest Mac OS to its customers who were willing to give it a shot. As we near the fall season, and the final release of Yosemite, Apple has made the public beta version available for those who are willing to give it a shot. It is worth noting, that there are several features that do not work perfectly well, such as Handoff with 2011 variants of the Macbook Air, with the Beta build and Apple is expected to iron those bugs out in the final release, this is exactly the reason why you should not install the build on the Mac you use for work. It is best done on a backup machine where you a couple of bugs and issues here and there will not be a deal breaker.
In case you wish to install the preview Beta version of Yosemite, you can do so by following the steps below to obtain your own promo code which you will need for the installation to take place:
Step 1: Go over to the official beta Preview page for Yosemite linked below and click on the sign up button to get started.
Step 2: Once you click on sign up, you will be taken to the log in page where you must enter your Apple ID credentials to get started into the programme.
Step 3: After signing in, you will be taken to a page where you must redeem a promotional code for downloading the public beta. The link for the same will be towards the bottom of the page after scrolling.
Step 4: You must be running Mac OSX 10.9 to be able to install Yosemite and have minimum RAM of 2 GB and space of 8 GB on your HDD/SDD on your Mac. You will be told about the other requirements and how to check your Mac for the same on the following page, once you have done that, click on the checkbox agreeing to the terms and conditions and click on the download link which will launch your App Store for downloading Yosemite. Enter your redeeming code when prompted for and allow for the download to complete, post which installation will take place automatically.