I need to install Windows on my 5k iMac. I started with bootcamp, and created a partition, but for some reason Windows did now want to get installed there. The problem was with the partition, and I found an article saying I need to delete BOOTCAMP partition from windows install interface and then install windows into empty space on the drive, which I did try. After that windows did not install, saying there is a problem with GPT/MBR partitions, and I went through this answer on superuser which did not help me install windows either. Then, I ended up with a couple of empty partitions, big and small. This is current partition map: Number Start (sector) End (sector) Size Code Name 1 40 409639 200.0 MiB EF00 EFI System Partition 2 409640 879315167 419.1 GiB AF00 Diagnostics 3 879315168 881244159 941.9 MiB AB00 Recovery HD 4 881506304 881711103 100.0 MiB EF00 EFI system partition 5 881711104 881743871 16.0 MiB 0C01 Microsoft reserved ... 6 882665472 882870271 100.0 MiB EF00 EFI system partition 7 882870272 883791871 450.0 MiB 2700 Basic data partition 8 883791872 883996671 100.0 MiB EF00 EFI system partition 9 883996672 884918271 450.0 MiB 2700 Basic data partition 10 884918272 885123071 100.0 MiB EF00 EFI system partition 11 885123072 976842879 43.7 GiB AF00 Apple_HFS_Untitled_2 The worst thing is that Disk Utility does not let me delete these small partitions. When I select them, the "minus" button is just grayed out. I decided to do a complete wipe of the drive and restore from time machine, but now, every time I make a bootable El Capitan thumb via createinstallmedia, when I try loading from it all I see is a crossed circle (as if the thumb is empty). Any idea what I might have broken in order to cause this happening? Thanks!