Partition method is independent of bios flavor.  In Windows 10 disk mgmt (booted from either legacy bios or uefi) you can partition hdd to gpt or mbr.  mbr can only partition hdd < 2TB. If you repartition hdd to new method, you lose all data (but hdd is not wiped). after new partition you need to format disk.
Hi, I have an Inspiron 3650. I need to convert my (2) GPT Disks to MBR. Will that work with "UEFI" or "Legacy"? (BIOS?) I'd rather keep UEFI. But I read MBR only works with BIOS. (Not UEFI.) So I'm guessing Legacy means BIOS. (Not UEFI.) I've used Legacy when I have to boot from USB. Or at least to create the option to boot for UEFI. I think I originally had my Disks at MBR. So what should I use before converting GPT to MBR? Please reply. Thanks   EDIT: I'm trying to convert my SSD and HD to Dynamic. (From Basic.) I'm getting the error: "The selected GPT formatted Disk contains a partition which is not of type 'Partition_Basic_Data_GUID' and is both preceeded and followed by a partition of type 'Partition_Basic_Data-Guid'." I think I need to convert GPT to MBR. Is there another way? I'm using Windows Disk Management. Is there any third-party software? I have Aomei Partition Assistant. Thanks again
Does "Legacy" BIOS work with MBR?