Need help upgrading
I have a 2009, iMac 27-inch with a ton of memory (700+gb free). OS X El Capitan ver 10.11.6 and cannot get my APP Store to come up so that I can upgrade the OS. I use this for simple things, purchased from work used.
Any suggestions on how to get it to upgrade? Recommendations for which OS I should upgrade to would be appreciated.
Thanks
:)
iMac Line (2012 and Later)