Woes! Where has my Windows 8.1 partition gone! I was on a windows game last night, everything was running smoothly, no problems at all. Shutdown normally and went to bed. Started my Mac Pro this morning by just powering it on (defaults to booting into OSX for work) and it was stuck in some kind of reboot loop saying there was a problem starting up. I held down alt key and booted into recover partition and looked at disk utility, it said there was a EFI boot error. I tried a repair which said it couldn't repair it. I then rebooted again holding ALT and just the Macintosh + Recovery partitions showed up as options. I tried booting into OSX and it loaded fine this time, went into disk utility and the BOOTCAMP partition is there, I can view all the files on it too. Any ideas how to repair the boot sector so I can get both OSX and Windows as options again? (I am currently creating a disk image of bootcamp to an external) New Mac Pro, 512GB SSD, Bootcamp and OSX on internal SSD. Windows is 8.1. I tried Parallels Desktop and deleted it when the trial ended about 2 weeks ago, I have added a secondary monitor last night via HDMI and thats it for the last couple of weeks. No other software installs. I scan for viruses almost daily using malware bytes software. I don't visit dodgy websites. So, no idea how this occurred between this morning and last night. The only thing I did was disconnect everything the day before for an office rearrange. I have not resized any partition since buying the mac. Any help would be much appreciated.