SOLVED: CPU upgrade 2.0GHz to 2.8Ghz ( C2D Extreme X7900 ) - iMac Intel 20" EMC 2133 and 2210 - iFixit
Can't update iOS. 2008 model iMac running Mountain Lion(?). Old version of Safari will hardly open any websites and can't download chrome due to old OS. Seems to be unable to run
iMac 7,1 (20-inch | 24-inch, Mid 2006)
iMac Intel 20" EMC 2133 and 2210 Hard Drive Replacement - iFixit Repair Guide