where can I buy my 4GB Ram
Where can I buy a 4GB Ram for my IMac, is it only available at Apple store?
What iMac? Some iMacs do NOT have user-serviceable RAM so you would be wasting your money to buy more.
"About this Mac" will show a sub-model that will tell us if you can upgrade RAM at all:
Basically, 21.5-inch iMacs made since Late 2012 are sealed units and even getting to the RAM is a job for a professional. 21.5-inch sub-models "Mid 2014" to "Late 2015" have no RAM slots so not even a professional can add RAM.
