Possible to convert gpt to mbr without losing data?

When converting a disk from GPT to MBR in Windows, there are several important considerations to keep in mind to avoid data loss, boot issues, or compatibility problems. Here’s a detailed breakdown of key points:

1. Data Loss Warning

All data will be erased after GPT to MBR conversion is completed. The clean command in diskpart removes all partitions.

Back up important files before proceeding.

If the disk contains an OS, you’ll need to reinstall Windows after conversion.

2. Disk Size Limitations

MBR supports disks up to 2TB – If your disk is larger, the extra space will be unusable.

GPT is required for disks >2TB.

If converting a large disk, consider shrinking partitions first (but MBR will still cap at 2TB).

3. Boot Mode Compatibility

MBR works with Legacy BIOS (CSM mode). If your system uses UEFI, Windows may not boot after conversion.

Check your BIOS settings:

Legacy/CSM mode → Compatible with MBR.

UEFI mode → Requires GPT (Windows won’t boot from MBR in UEFI without workarounds).