How do I convert MBR to GPT without data loss?

Use mbr2gpt /convert /disk:0 from elevated Command Prompt. For the boot drive, run from Windows PE. Back up data first.

What is the difference between GPT and MBR?

GPT supports drives over 2TB and up to 128 partitions. MBR is limited to 2TB and 4 primary partitions. UEFI requires GPT.

Windows Disk Management Errors — Virtual Disk Service & Formatting Failures

Errordisk

Overview

Fix common Disk Management errors including 'Virtual Disk Service error', 'The operation is not supported by the object', and partition/format failures.

Key Details

Disk Management (diskmgmt.msc) relies on the Virtual Disk Service (VDS)
Common error: 'Virtual Disk Service error: The operation is not supported by the object'
GPT disks support up to 128 partitions; MBR limited to 4 primary partitions
Cannot format a drive larger than 32GB to FAT32 using Disk Management (use diskpart or third-party)
Some operations require the volume to be unmounted first

Common Causes

Trying to create a 5th primary partition on MBR disk (max 4)
Formatting a large drive to FAT32 (Windows GUI limits FAT32 to 32GB)
Virtual Disk Service not running or crashed
Drive is write-protected at hardware or software level
Partition alignment issues with 4K sector drives

Steps

1For MBR 4-partition limit: convert to GPT (backup first) or use extended partition
2For FAT32 over 32GB: use diskpart (format fs=fat32 quick) or Rufus/third-party tool
3Restart Virtual Disk Service: services.msc > Virtual Disk > Restart
4For write-protected drives: diskpart > select disk N > attributes disk clear readonly
5Use diskpart for operations Disk Management cannot perform: clean, convert gpt/mbr, create partition