I think you mean convert MBR to GPT.
1. Convert MBR to GPT using Diskpart command
This method you have to backup all your data and delete all partitions and volumes.
Then use the DISKPART command
Open command prompt and type in DISKPART and press Enter
Then type in list disk (Note down the number of disk you want to convert to GPT)
Then type in select disk number of disk
Finally type in convert gpt.
2.Convert MBR disk to GPT disk with Windows Disk Management
Right click "My Computer" and choose "Manage" -> "Storage" -> "Disk Management".
Delete all volumes on the MBR hard disk which you want to convert to GPT disk.
Right click on the hard disk 1 and choose "Convert to GPT disk".
After you convert MBR disk to GPT disk, you can create partitions on the GPT disk if you like.
3.Third-party disk manage tool
EaseUS Partition Master and Paragon Partition Manager Strongly recommended.