I was messing around with reinstalling Windows 7 in bootcamp last night even though it's not officially supported anymore and somehow something went wrong and my computer is not booting most of the time. About 1 out of 5 times I can get into OSX, the other 4 times it plays the startup sounds and the screen stays black. After 10 sec or so the keyboard lights up and if I hit enter it'll make the ding sound so I know it's booting into OSX, but nothing is showing up on the screen. I tried using an external monitor and nothing. I've reset the PRAM multiple times, did the Shift+Option+Control+Power to reset to controller and that didn't help. I can't even get into recovery. I think the recovery partition got messed up. I can still see it in terminal, but I can't boot into it. It boots into internet recovery everytime I do cmd+r. It loads for a few min in internet recovery then reboots itself to OSX with a black screen. TL;DR Can't get into recovery to format disk, internet recovery doesn't work either. OSX is booting but screen boots black 90% of the time. How do I format the disk without recovery? Tried re downloading El cap from app store to do a clean install (couldn't format since it wasn't in recovery) but it didn't help.