El Capitan won't boot - repeated rebuilds - help!
Hi,
I hope someone can help me. Since installing El Capitan I cannot reboot my iMac. It runs fine when it runs, but as soon as I reboot it gets as far as the grey apple with the loading indicator line below, then back to a black screen and start up noise repeatedly. The only way I have found to repair the Mac is to boot into the repair utility and rebuild the OS - each time taking between 5 and 7 hours.
I have also run the disk utility which doesn't seem to throw up any problems (from both the repair utility and from within El Captian).
Any suggestions most gratefully received,
Thanks
TG
iMac, OS X El Capitan (10.11), 4GB Ram