How to convert mbr to gpt without operating system

Converting MBR to GPT using Windows PE definitely has its perks, but there are some downsides you should keep in mind.

1. If your system isn't set up for UEFI (like many older machines), this whole process might just be a headache. You'll need to make sure your BIOS settings allow for GPT, or else you might run into awkward boot issues. 

2. If something goes sideways during the conversion, recovery can be a pain since you’re not running an OS at that point. You’re just in WinPE, and that’s a stripped-down version of Windows. Not a ton of tools or options to troubleshoot if things go haywire.

3. The drivers for your hardware may not play nice in WinPE. If you’ve got specific hardware, like certain RAID controllers, they might not be properly supported in this environment. You could end up staring at a blank screen when you were hoping to see a disk to convert!

So, in summary, while converting MBR to GPT using Windows PE is pretty solid for disk management, it requires some technical know-how, preparation, and a pinch of bravery.