Converting from MBR to GPT Disks

You can convert disks only from MBR to GPT, or vice versa, if the disk does not contain partitions or volumes. You can convert a disk in two ways:

• In the Disk Management snap-in, right-click the MBR drive you want to convert to GPT and then click Convert To GPT Disk. If the drive is not empty or contains partitions, this option is unavailable.
• In the DiskPart command-line tool, select the drive you want to convert and run the command convert gpt. Similarly, to convert from GPT to MBR, run the command convert mbr.

Note When a dynamic disk is converted between MBR and GPT types, it must first be converted to a basic disk, then converted to MBR or GPT as appropriate, and then converted back to a dynamic disk. When you use the Disk Management snap-in, the conversion to a basic disk and then back to a dynamic disk happens automatically in the background. If you're using the command-line DiskPart tool, you must explicitly make the conversions.