How can I change mbr to gpt without data loss?

Even though MBR2GPT is pretty reliable when you change MBR to GPT on Windows PC, there's always a tiny chance something could mess up during the conversion. I've seen folks run into boot issues or partition problems if they didn't follow the steps carefully. Some older BIOS systems might not support booting from GPT disks. Make sure your motherboard and firmware are UEFI-compatible, or you might end up with a disk you can't boot from.

You mentioned having a backup before changing MBR to GPT, which is smart. I can't stress enough — if something unexpected happens, you’ll thank yourself for the backup. The tool requires a certain partition layout and free space for the conversion. If your disk is heavily partitioned or has weird setups, you might run into issues. Sometimes, after switching, Windows might not boot right away or might need some repair. Be prepared to run startup repair or fix boot records if needed.

While MBR2GPT is designed to be safe, reversing back from GPT to MBR isn't straightforward and can be risky or require data loss. I’ve used MBR2GPT a couple of times on clean installs or test systems — it works well if you follow the instructions carefully. But if your system is a bit funky or has lots of custom partitions, it’s worth doing some more research or even considering a fresh install just to be safe.