No physical memory is available at the location required for the Windows Boot Manager. The system can not continue.

That must have made the top ten list of merry-go-rounds of horror. It would have been more appropriate 5 days ago. Let's try the these. Boot to a Win 10 Installation USB drive, then...

(a) "Troubleshoot > Advanced Options > Command Prompt".

(b) Enter the following commands...

BootRec  /FixMBR        <<<Write a new MBR

BootRec  /FixBoot        <<<Write a new boot sector

DiskPart <<<Enter DiskPart

List Vol <<<List volumes & letters

Select Vol=x <<<Select the one that is Windows, not x

Active <<<Just in case that was lost

Select Vol=y <<<Select the IBM BM partition, not y

Inactive <<<Make it Inactive

Exit <<<Leave DiskPart

=== Which letter is on the Windows partition (338 GB)? ===

=== Use it instead of X: in the following commands ===

REN X:\Boot\BCD BCD_old4 <<<Or whatever number you're up to

BCDBoot  X:\Windows  /s  X:  /f  BIOS <<<Replace X: twice

That will create a new BCD as well as all the other boot files. Try to boot. Good luck.

Here's what I tried:

(1) Put the cloned HD of the bad one (which is still internal installed in the E6530) into the Lenovo laptop. Set Lenovo BIOS to Legacy only and CSM. Tried to boot Windows and got the Windows Boot Manager failed to start message screen.

(2) Attempted to boot off a Win recovery CD and run repair. It got stuck in an infinite loop of Automated Repair and I couldn't seem to get out of even after rebuilding the BCD.

(3) Attempted to Reset this PC. Wasn't quite sure what it was going to do. Maybe completely trash all my partitions? Just try to reinstall Windows in the proper partition? It started and then said it couldn't do it so nothing was done apparently.

(4) Booted Hiren's CD and ran the Lazesoft one click recovery. After "fixing it" (which it did not), I rebooted to (you guessed it) the Windows Boot Manager failed to start screen (again!).

(5) Tried another"automated" recovery tool. Got Windows 10 Blue logo then Blank BSOD instead of Windows Boot Manager failed to start screen.

(6) Reran LazeSoft one click recovery. Back to Windows Boot Manager failed to start message screen.

Jordan

I just reread this entire thread, but still can't quite come up with an answer. But it did drive me to a second half glass of wine, & that feels good anyhow.

(1) I come up blank contemplating whether the Windows partition is meant to be Startable at all when the IBM Boot Manager is being used to do the dual boot. And -- even if it should be made Startable -- I can't decide what should be in its VBR -- the IBM or the Windows Boot Manager.

(2) The Windows Boot Manager, you know, won't boot your eCS partition because it is not a primary partition. It would be nice to see whether it can boot the Windows partition, though. If so, maybe a 3rd-party tool can delete System Reserved, then turn your eCS into a primary. Then EasyBCD can add it to a dual boot. But that would be the limit. You won't be able to triple boot. And I'm not really confident you can sneak into that os2world installation this way.

(3) As you say, using the Windows RE or even Hirens on an eCS installation could damage it by putting code into the Boot Sector or the VBR that doesn't belong. But I think that's less likely when the Windows boot manager is being used. At least, that os2world article did say the BCDBoot command could be used.

(1) Yes. The Lenovo is very flexible. It has UEFI then Legacy boot or just Legacy Boot and CSM support either way, I tried just UEFI/Legacy and just Legacy (both with CSM). Neither worked.

(2) Indeed. If only there was a way to "undo" that.

(3) I will try putting the external HD in the Lenovo directly to see if anything changes.

(4) Actually, I tried to repair the internal bad HD with WinRE. I have read on the Internet that it is not that good at fixing things. I guess that is why there are multiple 3rd party software packages available to attempt repairs, but so far I haven't found one that can deal with (i.e. fix) mine. I keep wondering whether they really care about old Legacy/BIOS boot systems and just try to mess with them with UEFI. That may have contributed to the problem that I am seeing as I have tried at least of couple of them with no success and I can not remember if the signature of the problem changed after trying them. Seems like it might have resulted in the "No physical..." message.

Jordan

I don't like the idea of booting Windows from an external HDD. If it does boot, confusion might arise when doing a reboot owing to the presence of the internal installation. It might grab the wrong BCD, I think. But maybe the risk is less in a Legacy installation. I don't know.

(1) But my first thought is -- did you set BIOS to boot in Legacy Mode &/or enable CMS? BIOS must match the mode of the installation.

(2) The fact that Windows (not IBM) Boot Manager was named in the error message is interesting. It sounds like the VBR (volume boot record) of that Windows partition still wants to invoke the Windows Boot Manager.

(3) Obviously, there is a massive hardware change. But I thought Windows was supposed to switch the drivers automatically. Maybe it refuses because the drive is external.

(4) Trying to repair it in a recovery environment fails, I think, because it wants to repair the internal installation, not the external one that is broke.