IF YOU ARE STUCK ON STARTUP SCRIPTS READ THIS!
push the windows key and type C:\programdata/battle.net/agent
open the file and look for agent 913 and double click agent.
when it is done flushing press ctrl alt delete for your task manager now make sure agent.exe is ended and after you finish that open agent again
now use the open as administrator for the diablo intstall
wait a bit and if the agent window says 100.0000 with a bunch of other crap it should work

if anyone has problems add my skype zach.smith73 ill help as much as possible