Is this article a good enough guide to get this done? Windows 10 was installed to a Legacy MBR partition table but now I like to switch that to GPT without data loss if possible. Are there any side effects to this? Also should the conversion complete as intended in command prompt isn't is necessary before first boot up to enter the BIOS settings and make that change in there too? Thanks Regards EASTER
Try the new "MBR2GPT" command built-in in Windows 10 1703. The process is non-destructive (no data loss) and can be run from Windows 1703 or from a boot USB WinPE 10 1703 (better). Note that it may be necessary to do some changes to the partition layout before doing the conversion. In particular: - The process does not work with logical partitions. If you have them, you must convert them to primaries (if possible) or delete them and restore them from backups after the conversion. - You cannot have more than 3 primary partitions before the conversion. If you have 4, the process wont´work. This is because the ESP (EFI System Partition) is created as a primary before the conversion to GPT. You can validate the layout before doing the conversion. MBR2GPT.EXE. Windows 10: Convert Windows 10 from Legacy BIOS to UEFI without Data Loss
Robin A. -Thanks for the reply and accompanying links too. Looks like with that win creators update it's as well to get it put on and done with in order to do two birds with one stone so to speak. Being a long seasoned avid Windows customization fan has it's common drawbacks (something we're used to now) but maybe this upgrade can stick around longer. Appreciate the timely advice.
No. If you try the conversion - you may find out Windows won't boot. Is there a point to messing around with the default file table? I don't see it. Leave the Master Boot Record well enough alone.
Maybe is not in the plan. There will always be risk delving into that element of the disk and geometry but depending on the method used, a risk is worth the effort to confirm whether or not a routine is performed to each step and getting a result either way determines the value of the information of that process described. The point is nothing is at any real risk regardless because Macrium Reflect BackUp Images are always at the ready just in case.
There is also a "Macrium procedure" to convert from MBR to GPT: Restoring an MBR System to UEFI/GPT This is a destructive process, the disk is cleaned at the beginning and after the conversion the partitions are restored to the GPT disk from image backups. I tried this once and Windows booted after the conversion. But the WinRE was disabled and I couldn´t correct this problem. This is another procedure similar to the describe in the first post, but simpler: Converting Windows BIOS installation to UEFI. But, if you are on Windows 10 1703, the MBR2GPT.EXE procedure is much better. Very simple, only one command, and the conversion is done in seconds.
There is one HUGE, glaring omission. Step 1. Backup any data you don't want to lose. Step 2. Verify backup.
100% No Brainer but yes for sake of readers to this, a glaring omission but now updated. If a user even vaguely entertains a thought to making disk changes of this nature let's expect they took provisions to do just that.
The TeraByte Unlimited change disk type script does a nice job. I just converted a Win10 1703 MBR disk to GPT. The MBR disk had 4 primary partitions including one Extended partition. The Extended partition contained 3 logical volumes. That is 6 partitions with drive letters. There was 500 MiB of unallocated free space on the disk. Conversion to GPT took two seconds. Each logical volume was converted to a primary partition. After changing BIOS firmware settings to enable Secure Boot, Win10 booted fine. The MSR and ESP were created in the unallocated free space.
You have to have a BIBM license to use the script. Edit... My mistake. It is included in BIBM, IFW, IFL and IFD.
It´s not included in IFW (that is, in the Suite that also incudes IFL). It´s one of the 25+ shortcuts that appear when the Suite is installed, but it doesn´t work, like some others. It requires the BIBM license. Edit. I checked again, confirmed.
Partition Wizard Free can convert data MBR disks to GPT, but not boot MBR disks. The same is true of other partition managers. Now, PW Pro (not Free) v. 10.x claims to be able to convert boot MBR disks, but some reports indicate that the process doesn´t work. I haven´t tried it, and the info in the website is confusing.
Its absurd to make the claim there is no data loss. Anytime you change something, its not going to be like it was before. There are certain things I don't mess around with in Windows.
It can be done with no data loss. The only exception would be in the highly unlikely case that something went wrong. But, that's what backups are for.
It is not absurd at all! In fact it is typical for there to be no data loss. As roger correctly noted, it is only when something goes wrong that any data loss occurs. Changing something is not the same thing as data loss. I have converted many hard drives over the years from FAT-32 to NTFS. Major changes were done, but not a single loss of data occurred. When you change partition sizes, data is moved all around, files are fragmented and then defragmented then fragmented again. Yet typically result in no data loss.
Worked on this end too. It's just that you really have to wrap your noggin around what you're trying to accomplish, watch closely everything is followed by steps and forget about shortcuts.
