Converting GPT to MBR for 1 partition without losing data from other partitions

Question

Is it possible to convert a single partition from GPT to MBR without losing data from other partitions?

I had installed windwos 10 and Ubuntu as dual boot and i wanted to reinstall windows 10 and formatted the partition where it was installed, so i have no windows anymore. After that i saw that i am unable to install win10 on this partition getting the following message "windows cannot be installed on this disk. The selected disk is of the GPT partition style."

Also to mention that i cannot change the boot mode to UEFI because i have no such option in boot settings from bios: My settings in BIOS

I disabled launch csm also.

I have two partitions for windows, the one where i want to install it, which is already formatted and another one with about 600GB of data which i don't want to lose.

Thanks!

• Ramhound: Linux and Windows both support GPT. Why do you want to convert back to MBR. If you are getting the "windows cannot be installed on this disk" it means the disk has not been booted in UEFI mode, which is odd, since thats the only way to boot to your current installation.

Answer 1

You can't change one partition from GPT to MBR, because GPT and MBR are not properties of a single partition on a disk, they are names for two different types of partition tables.

It is possible to create both GPT and MBR tables on the same disk, but they should better describe the same partitions, or the MBR a subset of the GPT. MBR is more limited, so it may not be possible to describe every partition from the GPT.

It is possible to delete own partition table and create a new table of a different type with the partitions in the same place and the data intact. However it is also easy to make a mistake somewhere and lose all data, so it's better to back up everything and then copy back to the repartitioned disk.

• TOOGAM: This is mostly accurate, although a GPT-based setup might make some assumptions about a co-existing MBR. Apparently the details of those required assumptions may vary a bit based on implementation. In a nutshell, I could convert from GPT to MBR successfully with the right tools, as long as the disk could work with MBR (e.g. the disk isn't too big). But it is very easy to make a mistake. I'd be writing numbers down. I wouldn't want to do so without first making a disk backup. Know that using FDISK has been known to cause minor data loss (512 bytes at partition start), so beware of that.

Answer 2

Thank you for answering.

It seems that i found the problem, i didn't use proper settings in rufus when i created the bootable media. It was set on "MBR partition scheme for BIOS or UEFI" instead of "GPT partition scheme for UEFI" which created the incompatibility.