During reinstall of windows 7 I arrived at the following statement “Windows cannot be installed to this disk. Disk is of the GPT partition style”. Does this mean Windows 7 only installs with MBR system or that I should starting in bios and not be using bios and not UEFI. How do I get beyond this point. Note that I am trying to install windows on a disk previously occupied by Ubuntu 14.04.2. My ultimate goal is to partition my disk (1000 GB) into three approximately equal parts; one with windows 7, one with windows 10 and one with Ubuntu 14.04.3. Is this reasonable once I understand the ins and outs of bios vs UEFI, MBR vs GPT, FAT32 vs NTFS and what an EFI System partition is?