Creator's Update Changed Drive From GPT to MBR and Deleted Partition

[shreksaget]

I installed the creators update last night, and I realized my 746 GB partition on my 3TB hard drive has vanished. I looked in windows disk management to re-partition the drive, and right clicking to do it is grayed out, similar to what you would get if the drive was set to MBR. I did some googling and downloaded Mini Tool Partition Wizard, and it told me that the disk uses MBR format. Before the update I had the drive set to GPT and had loads of steam games installed on it, and now it's not even in the right format?! How is this even possible?

I didn't lose any valuable files, but is there anything I can do to fix this or do I need to wipe my drive and start again?

 

[Colif]

I don't know how it swapped the format of a drive without needing to format it... was this the boot drive?

You can use the mbr2gpt tool thats built into creators edition to convert it back to gpt without losing data - https://www.tenforums.com/tutorials/81502-convert-windows-10-legacy-bios-uefi-without-data-loss.html

its not that it deleted the partition, its more MBR cannot see anything over 2tb on a hdd, its why it was GPT to begin with. So the partition might come back.

 

[traumadisaster]

I think same happened to me with Fall Creators update, I'm missing a partition as well. When I look at the the remaining partition in properties it shows their was a migration that occurred at the time of the win10 update. I'm not sure what a migration is but I'm wondering if the missing partition can not be read since it's in mbr now?

 

[Colif]

I think same happened to me with Fall Creators update, I'm missing a partition as well. When I look at the the remaining partition in properties it shows their was a migration that occurred at the time of the win10 update. I'm not sure what a migration is but I'm wondering if the missing partition can not be read since it's in mbr now?

You might get more people helping if you make a new thread about this. I would ask you to put a image of disk management in the post as well as it will show us what you are seeing. If you show a link here I will see what I can do

That migration might have been part of the update process as Version updates install a new version of windows and have to move user files into the new locations.