Late 2015 2.8 GHZ i5 Intel iMac with 16gb memory iMac running El Capitain ball spinning randomly when moving files around and clicking on toolbars, running word and other things. Considering upping to Mojave....not sure what exactly it is. HD is not yet 3/4 full but getting there. Haven't yet run any utilities as it's not my computer asking for a friend.
