Hello guys I am writing for desperation, I hope you can help me. Then I have an iMac 27 mid 2010 where I have always done the Bootcamp, installing Windows 7 and then 8.1. When one day I decided to replace the super-drive with a 512 GB SSD Crucial. After I installed OSX on SSD to increase the performance and fully formatted HDD 1TB which also shortly after he started to give me a malfunction. After that they are no longer able to install windows 10 on the SSD using Bootcamp always giving me the same error when I run the windows installation CD: "Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to gpt disk" I have tried everything to solve the problem trying to change the SSD partition table also completely reinstalling OSX also I was told that the problem could be the presence of two HDD in the iMac so I immediately removed HDD that was unused, but the problem persists. I hope you can help me because this problem is pulling me crazy!