On a mid 2010 i7 iMac, going from 10.10.5 to 10.11 (with all peripherals disconnected). I can't get El Capitán to finish the install-- Twice this has happened, with identical results: once on an internal volume and once on an external FW volume. Short History: All seems to be going well, the DL was uneventful as was most of the install. But then, during the second restart, the installer stalls (hangs?) with about 7 minutes estimated time remaining. Two hours later, no progress or change. I manually restarted, but that always reverts to the same previously stalled window. From a different volume, I could see that System Preferences identified the startup disk with El Capitán on it, but I still can’t get the install to complete. I tried repairing the El Capitán volume with Disk Warrior, but that did no good. What am I doing wrong?