I recently purchased a 3TB WD internal drive as a media storage. I thought this would be no problem since i have a UEFI Bios (ASRock P67 Pro3). After not being able to use any of the storage beyond 2TB (not even creating 2 partition totaling 3TB) i looked into the BIOS and SATA mode is in IDE. I assume that's why Windows disk management won't let me convert the MBR disk to GPT ? I'm using Win7 64bit.
So i changed SATA mode to AHCI and windows wouldn't boot up anymore. I boot from a crucial m4 CT064M4SSD2 which supports AHCI i believe. Do i have to re-install Windows ? Maybe its something i could do while upgrading to Win10 ? Is switching sata mode after installing supported in Win10 as opposed to Win7 ? i'd like to be sure the problem comes from not having AHCI mode on before nuking windows. I'd rather keep Win7 for now but i can upgrade too.