Get the return message “Found invalid GPT and valid MBR; converting MBR to GPT format in memory” when you use GDisk to convert MBR to GPT in Windows? Learn why the error occur and how to solve it in a simple way.
“I’d like to convert my hard drive to GPT partition style with GDisk command. After I input gdisk32.exe 0: and press Enter, only to get this return message: Found invalid GPT and valid MBR; converting MBR to GPT format in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by typing 'q' if you don’t want to convert your MBR partitions to GPT format!
It says the operation may destroy my data, so I typed ‘q’ to exit. Why would that happen? And what should I do to get my disk partition style changed from MBR to GPT, better without losing data?”
It is an error that may occur when using command lines with GDisk, SGDisk, or Clonezilla. Why would you get this GDisk Found invalid GPT and valid MBR error? Is there any way to get you out of trouble? Keep reading.
Before learning how to fix the error, you may wonder the reasons account for the error. In general, there are two possible causes to explain your problem:
1. You did not launch with administrative privileges. Under Windows, you need to right-click the Command Prompt program and select the “Run as Administrator” option, and then use the resulting window to run gdisk.
2. Your computer motherboard or operating system does not support UEFI boot. This is a cause explained after the error message. Most previous versions of Windows cannot boot from a GPT disk except on a UEFI-based computer, and most varieties before Vista cannot read GPT disks. Therefore, confirm these qualifications before you start. (Click the Start button and go to All Apps> Windows Administrative Tools > System Information> BIOS Mode)
If you cannot fix the “invalid GPT and valid MBR” error after all trying, it is a wise option to turn to MBR to GPT converting software. AOMEI Partition Assistant Professional is a user-friendly software that allows you to convert the hard drive from MBR to GPT without losing data, regardless of system disk or data disk. Windows 11/10/8.1/8/7/XP/Vista supported. Let’s get to know the specific steps now.
1. Install and run AOMEI Partition Assistant on your computer. Find the disk you want to convert, right-click it, and select "Convert to GPT" from the menu, or click the disk and choose "Convert to GPT" from the right panel.
2. Click "OK" to continue the operation.
3. Click "Apply" and then "Proceed" to commit. After that, shut down your computer after conversion. Change Legacy to UEFI if you have converted the system disk to GPT partition style.
Run gdisk with administrative privilege or make sure your Windows version and motherboard support UEFI boot when you face the prompt: Found invalid GPT and valid MBR. Also, an easier way to convert MBR to GPT is provided followed by AOMEI Partition Assistant if you cannot get out of the trouble caused by gdisk or Clonezilla.
Except for MBR & GPT converting, you can also perform OS migration to SSD while keeping files on HDD with AOMEI Partition Assistant to gain better performance. Changing partition file system without formatting, clone disk/partition, SSD secure erase, and moving programs without reinstalling, etc are also available.