I have a Macbook Pro with an SSD drive installed. The laptop runs OS X 10.11 (El Capitan) and Windows 7 on a Bootcamp partition. Something weird was going on however. The drive itself is 512GB, but the only partitions I could see in OSX where a 170GB Macintosh HD and a 90GB BOOTCAMP.
When booting in Windows, I saw there was about 200GB of 'unused' space. I created a partition in Windows and formatted it. All good.
After rebooting, however, my Macintosh HD disappeared and the Windows partition boots, but doesn't get to the login screen (instead it goes to recovery mode).
My feeling is that Windows replaced the GUID partition map with an MBR one, which essentially makes partitions unmountable. OS X still recognizes the partition layout, however, as can be seen in the screenshot below:
Is there any way to recover the original partition map?