Shall I just use Safari (which is garbage). To dump us because we can't buy a new computer to run a newer OS that is a memory hog is quite frankly, a shame. Some of us remember the Netscape/Internet Explorer war and CHOOSE Mozilla Firefox with intent. It is unreasonable for Firefox support to have been dropped for MAC OS systems prior to 10.9 - it's a browser, it should always be backward compatible. I can't spend $3,000 with Apple to get a MacBook with 16GB to give up 250GB of hard drive space for the same size screen just to run the newer OS and update Firefox. I have a 2012 MacBook running 10.8.5 because it only has 8GB and can not run a newer version of the OS. You may have been prompted to run a firmware update while using Software Update but just in case you can check if your Firmware version is up to date on Apple’s EFI and SMC firmware updates article.I think telling someone who has clearly indicated he/she can not update their computer to update their computer is a but unreasonable. Some Macs may require a firmware update to run Lion. If you don’t have enough “Available” space, we can help you upgrade your drive in about 1 day. To check how much free space your Mac has, select your hard drive and choose File > Get Info. You’ll need 5GB of free disk space just to download the Lion installer but you’ll want at least 20GB available to safely run the upgrade and continue using your Mac. The more RAM you install the faster your computer will run. You can view your Mac’s RAM right under Processor in the About This Mac. Officially Lion requires a minimum of 2GB of RAM to run. PowerPC Macs (such as the iBook and PowerBook) manufactured before 2006 are also not compatible.

The earliest Intel Macs with Core Solo and Core Duo (without the 2) processors will not run Lion. Your processor must be an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon processor to run Lion. Go to the Apple in the Upper left corner of your screen and select About This Mac to view your processor’s type.

Lion can only be run on certain Intel Processors. If you are running Leopard (OS X 10.5), you must buy Snow Leopard on DVD before you can update to Lion.

Click the Apple in the upper left corner of your Mac and select Software Update to upgrade to 10.6.8. Your Mac must be running OS X 10.6.8 Snow Leopard in order to purchase OS X Lion from the Mac App Store. Check the following spots on your Mac before attempting to upgrade to Lion.

Mac os 10.6.8 software update