Forum Discussion
MBR2GPT Disk layout validation failed
Regardless, it is your responsibility to make sure you know what you are doing, and always take a backup before performing changes at this level.
Please learn to be respectful, we are all community members trying belp each other in absense of Microsoft.
Thank you for all the help you provided to solve this problem. I have the same message of disk validation failed (see screenshot). And I get this message absolutely regardless from where I try it, within Windows, PE, or recovery. The message WILL REMAIN THE SAME. I even copied the whole HDD to an USB HDD and tried to change that to GPT running the mbr2gpt command, still got the same result. Shrinking the partition and deleting one partition did not help either. not did shrinking the 2nd partition after deleting the 3rd. Are there any further ideas how I can get this to work?
If there are any information missing, please let me know, I will give them to you, as soon as I can and thank you very much for your support!
P.S.
Yes, I deleted the recovery partition years ago and Windows 10 is running just like that in Legacy mode. And also yes, my HW is pretty recent for this PC and supports both UEFI and BIOS, if a detailed information on motherboard/HDDs used is needed, please let me know, though I doubt it is due to the type of mainboard/harddisk that I get this error message.
Stefan_Mocellin I just solved this issue with a key bit of info from @SalmanAhmed
I had a weird 98mb allocation of free space that was highlighted green in the disk management window and thought this might be the problem. I converted it into a new partition to see if this would enable me to validate successfully, which still failed. I then realized it was a "logical" partition and not primary as Salman mentioned above. I barely have any idea what all this means so i googled how to convert a logical to primary using diskpart. https://www.diskpart.com/articles/convert-logical-partition-to-primary-using-diskpart-1881.html
During this process I noticed (and I have no idea why) an "extended" partition in the "list partition" part of diskpart, which didn't show at all in the Disk Management window. Anyway i deleted that and ended up with only three primary partitions that were highlighted in dark blue in Disk Management. So, as a complete novice at this, all i can offer is for you to convert your D and E drives to "primary" partitions as they appear to be a lighter blue "logical" partitions. Good luck! (note that the logical to primary partition conversion requires formatting).
Hello and thank you very much for your kind reply. I did delete both partitions (after backing up the data ofc) and then enlarged the C: partition, tried to recreate both partitions, now as primary, but always ran into the following error:
"Cannot find OS partition(s) for disk 0"
I think this is due to the missing Recovery partition, is there an easy way to get that back, I never needed it (till now) and deleted it years ago. Please find the screenshot below and deleting both partitions on DISK:0 will still result in the same error, most likely due to the missing recovery partition. And if possible without Aomai Partition Manager that SW will only work if I pay ~~50€ which I am not willing to pay for a tool that will not work on my PC.
Thank you very much for your help!
From the screen you've shared, the following points seems pretty good for disk 0:
- There must be a maximum of three partitions in the MBR partition table
- You should not have any extended/logical partition, all three partitions must be primary partitions.
Please confirm the following requirement on disk 0:
- You must have active partition on disk 0
- There must be a system partition (OS Partition), and its recommended to boot from the same disk (disk0) while converting MBR to GPT.
Please have a look and let me know your feedback.
Hi dralbot!
I'm glad to hear that the above solution was helpful for you. Thank you so much for sharing your experience and feedback.
-Salman
