BootMGR Corrupt or Missing-Legacy BIOS only PC Failed Installation

[Grant58302]

I've used Flyby11 on several PC's and it's worked fine on the ones with a UEIF setup configuration, but it didn't work on a Dell Precision 3500 which has only a legacy BIOS. The installation tried to reboot and couldn't, with the announcement that the BootMGR was missing or corrupted. Couldn't repair the boot sector even with the command prompt. Finally had to reinstall Windows 10.
Will the patch offered by the Flyby1 installer solve this issue?
If the patch won't work for that, have you gotten the Win11 upgrade to work on legacy BIOS and how did you manage it?
Thanks for your time!
Grant

[Stevenwsmtih]

I've had the same problem with MBR(Legacy) PCs. Has this issue been solved? Can you use Flyby22 on older PCs that only have legacy BIOS mode instead of GPT(UEFI)?

[Grant58302]

Hi, Mr. Smith! Sadly, no. I gave up on it. In my investigation of the issue I ran across a few posts in different forums that were tendered as opinions but that I think might be true. They opined that the newer builds of Windows 11 -- especially 24H2-- have been modified such that they will no longer boot to legacy BIOS. All the methods I've tried which purport to allow Win11 to run on Legacy BIOS successfully side-step the common installation restrictions and will load the OS on the HDD, it's only when when all the files are loaded and it comes time for that first boot that things fall apart.

You may notice that all the YouTube videos and written tutorials that advertise their method as being able to fully install and run Win11 on legacy systems are several years old. No recent ones using 24H2. I think that's probably because none of these methods work with 24H2. I'm not sure what would happen if you could find whatever version of Win11 was out a few years ago and then followed some of those tutorials. Even if you could get that build to fully install on your legacy system, what would happen when you tried to update to the current build? Would you run into the same issue when you restarted after the updates or would the updated OS just go with it? Interesting question, but not interesting enough to me to try it. Fortunately I have a few other PC's that had Windows 10 on them but are modern enough to have UEFI as an option. Those I was able to upgrade to 24H2 either through Flyby11 or RUFUS and they are still working with no issues. Basically I just got a bit stubborn about the legacy-only PC (a Dell Precision T1400) because there were these videos, etc., saying that it could be successfully updated. Fortunately my stubbornness has its limits.

If you were an IT whiz you might be able to tweak things so that 24H2 would accept a legacy BIOS, but I ain't one and I haven't seen any tutorials from any on the matter, so, I'm done with it. If you find something that works, please respond to this post again so I can check it out.

Good luck!