You can check if a disk uses GPT or MBR partition in Windows 11/10 effortlessly, using Disk Management, Device Manager, CMD or PowerShell.

4 tools to convert MBR to GPT that you can’t miss In the following, we’ll focus on assisting you in securely converting MBR to GPT without losing data using 4 different methods.

The selected GPT formatted disk contains a partition which is not of type PARTITION_BASIC_DATA_GUID This is reported mostly when the user is trying to extend a specific disk-partition.

The only online references I've found to "GPT protective partition" have been in relation to trying to read GPT-formatted partitions on Windows XP, which doesn't support GPT.

EaseUS' Solution To address these challenges, EaseUS Partition Master offers a reliable and user-friendly solution. This disk management software can convert MBR to GPT without losing any data.