Windows 10: After general system instability and hourly BSODs, I decided I would rebuild my BCD. When I...

submitted by /u/GoldenSpamfish
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:)

 

How to clean up BCD entries? Rebuild the BCD?

This is normal that under Recovery Environment, The letters are re-assigned. This is why you have to be careful and select the correct one.
@dictum
Advice: Never use Easy BCD with Windows installed using GPT disk. Use Easy UEFI instead provided you know what you are doing. Easy BCD only works with MBR disk type.
Base on the screen shot above. Your disk 0 is your new Windows and your disk 1 contains the old Windows. Disk 3 contains a 512MB Fat32 partition and I don't know what that is. I suggest you disconnect disk 3 for now before proceeding.

Let rebuild new BCD's for both disk 0, and disk 1. Please follow step by step on the 2 screen shots below. On step 3, write down the drive letter for PM981_New. In the screen shot, My Windows is still assigned to C but it might be different from yours. In step 10, if the drive letter is different than C, then use the letter in step 3.

Do exactly the same for disk 1, this time select disk 1 in step 4 and assign letter V in step 7, Use V and the drive letter for Old Windows in step 10. This will create a new BCD for PM981_Old and you will be able to boot separately from boot menu.

From boot menu, select which one to boot from.
Once booted into Windows. If you wish, you can set up dual boot for Windows old & New. Under This PC, look for the drive letter of the offline Windows and type:
bcdboot X:\Windows where X is the letter of the offline Windows

 

BCD File Rebuild and BIOS

Our IT department updated my pc to 1803 not realizing that I have an X299 motherboard and a Samsung NVME SSD boot drive. I came in the next day to get the BCD File error BSOD with error code 0xc000098 (a known bug but not fixed a year after discovery).
Our IT department looked up this issue and decided to rebuild my BCD file and was (we thought) successful implementing this solution. My pc then booted from the previous NVME SSD drive. I had migrated my OS from the 256GB SSD to a new 500gb SSD, both NVME.
No troubles for a year booting from the 500gb disk and now it boots from the old 256gb drive which I did not wipe on purpose. I boot into the UEFI ASUS bios on the pc and the boot order configuration only lists one option for position 1 to 4. Before each position
listed each bootable device. First of all why in the world would a Windows update and BCD file rebuild screw with the BIOS and second how do I get the proper C: drive boot with to way to change the boot order in the BIOS?

 

How to clean up BCD entries? Rebuild the BCD?

I was able to get into it, except it's called F: and not C: in my case.















Hitting F11 upon boot cycle to get into bootable devices menu results in some bogus devices:




Attachment 251576

and selecting one of the bogus devices results in a unbootable menu choice:







This disk does not exist and I have to hit Control-Alt-delete several times to get back to the boot menu.
Basically nothing is resolved, I still have bogus entry in the BCD store. Or whatever it's called. NVRAM I think it is.

- - - Updated - - -


as for the second part:








didn't work.

This is what the correct boot entry looks like. The PM981_old entry doesn't boot anything, even though I added it with EasyBCD. That's fine, at least the primary boots (called PM981_new, the highlighted option).






This is an example of a bogus, non-existent entry that I can't delete. The disks it points to don't exist.

Bunch of junk, bogus, non-existent entries, the good one is not even the first one in the list:









For example if I select #1 in the above list, I get this:





and it doesn't go anywhere, can't find the disk since it doesn't exist and I don't know how to purge it out of ther.e


I re-burned the Windows recovery thing onto the flash and able to boot off it again: