Q: I currently have an iMac which was purchased in late 2009.  What software updates do I need to purchase/download?

The first thing you need to do is upgrade the ram. It looks like you have an early 2008 20" iMac that will use up t 6Gb of ram and you should upgrade to that. Only buy ram from trusted vendors such as Mac specialist OWC http://eshop.macsales.com/ or Crucial http://www.crucial.com/ and only use ram that meets your Macs EXACT spec. Buying other bargain basement brands of ram could leave you with kernel panics.

Once you have upgraded the ram you need to start by upgrading to Snow Leopard 10.6.3 http://www.apple.com/shop/product/MC573Z/A/mac-os-x-106-snow-leopard Once you have that installed run Software update to get to 10.6.8 and have access to the Mac App Store where you can upgrade to Lion 10.7 or Mountain Lion 10.8 for an additional $20 each or upgrade to the current OS El Capitan 10.11.2 for free.

Mike,

Thanks for the reply to this post - I may be wrong, but at least with my 2009 macbook, OSX 10.7.5 is the most I can upgrade to, with 6GB RAM. My computer won't install Maverick, nor Yosemite/El Capitan.

I've had this issue since Mavericks came out. I gather that older versions (-2009) of Macs are not compatible with newer OS's, despite Apple's claims that they are.

Is there a way for me to get OSX 10.7.6+? I want to check each update incrementally to update as much as possible, but I can't find any old updates anywhere on the Apple site. Thanks for any tips.

Peter

Your 2008 Macbook cannot run a version higher than 10.7.5 which is the final version of Lion. Sorry.