I installed 10.11 on my laptop, and everything seemed to go ok with it, bar the installer being extremely slow - it took around 2 hours to install with the progress bar remaining on '23 minutes remain' for around an hour and a half. Now when it boots, it going fine until about the loading bar is maybe 2/3 done, then slows to a crawl and takes another 20 minutes or so to reach full - where it stays. I have no cursor or anything else during this time, but my caps lock button light will go on an off when I press it. I've tried: -Resetting PRAM/NVRAM -Booting into recovery mode and repairing the drive/partition -Re-installing Yosemite. Naturally, this says that it can't be written over a higher OS version. -Booting hardware diagnostics and doing a check. It says everything is fine. -Safe boot. Takes the same length of time and hangs at the same place, so honestly not sure if I'm even doing it right. -Verbose mode says every single process has crashed, with 'too many corpses being created.'. Picture:http://i.imgur.com/WXvTTe5.jpg It's a Mid-2011 15" Macbook pro, 2.2GHz with a 750GB hard drive and 16GB of RAM. I'm still doing a few other checks (currently re-installing 10.11 to see if that fixes it), but has anyone got any ideas or had a similar problem?