How to change or convert mbr to gpt without data loss?

If you are looking for a free methods to change MBR to GPT without data loss, your options are quite limited, as most reliable tools are either mainstream or involve risks. However, here are some less common approaches that might work, but please proceed with caution and backup your data first:

Some open-source tools or scripts are less known but can help convert disks:

Such as GPT fdisk (gdisk):

This is a command-line utility available for Windows that can change MBR to GPT.

How to use:  

1. Download GPT fdisk from github's website.
2. Run gdisk on your disk. It has an option to convert MBR to GPT.
3. During the process, select the "Convert MBR to GPT" option.
4. It can preserve data if used carefully, but manual partition editing is risky.
5. Important: Read the documentation thoroughly before proceeding.