So I installed Elementary OS alongside Windows 10 on a Dell Latitude E5440. In the process, I used gdisk to convert the hdd from an mbr partition map to gpt (in Linux). After install, GRUB2 has no problem booting Elementary but Windows won't boot at all. I opened the BIOS settings and discovered that I'd been booting in legacy BIOS mode. I tried switching to UEFI, but obviously that didn't work as Elementary and Windows are both installed with legacy bootloaders. I did some poking around and learned that Windows doesn't support booting from a gpt hdd in legacy mode (Linux does). Obviously I need to convert the Windows Boot Manager somehow, but since I can't get Windows to boot my only idea was to edit the boot manager and any other necessary files from my Linux install. I am able to mount and access the Windows partitions in Linux. Could this work? And if so, what files should be changed/added/removed? Are there any other more viable solutions? Thanks.