XPS 8900, Windows 10 2004, no boot

Glad you got it working again.

Don't understand where BIOS 2.7.1 came from. Unlikely the Win 10 v2004 update installed it. More likely that Dell SupportAssist/Dell Update did it.

There have been times when the support page is behind and there are newer updates than listed. I've seen this happen when a user gets a brand new PC with a version of BIOS or driver that isn't (yet) listed on the support page... 

So now, hold off on v2004 for a while and let other peeps be Microsoft's Guinea pigs!   

Thanks for your reply. I was able to use the Windows Recovery Environment by power cycling the PC three times. Once in the RE I was able to roll back the update to 1909 and all is well.

Just FYI, I did have a complete backup of my data so wasn't too worried about things.

Thanks again.

Thanks for your reply. Per my other response, I was able to resolve the issue using the Windows Recovery Environment to roll back the update. It all worked smoothly.

I, too, have never seen a Windows Update include a BIOS update but I am 99.99% sure that is what happened. There may also have been a system firmware update but my BIOS did update from 2.6.1 to 2.7.1. I saw it on the screen after I rebooted. This was confirmed by entering the BIOS and checking.

I was able to downgrade the BIOS back to 2.6.1 and all is well.

Thanks again.

Same firmware update was offered to me and updated via windows update after a manual check. No issues so far but I am still on Win 10 1909, not 2004.  Related article describes the update and affected systems. 8900 is listed. 

https://www.dell.com/support/article/en-us/sln319429/dsa-2019-147-dell-client-platform-security-update-for-intel-platform-updates-2019-2?lang=en

Same here.  Two XPS-8900's and was surprised to have "Windows Update" TELL me a BIOS update was ready and WOULD be installed on next reboot.  No CHOICE.  

Both still on Win10 1909.  Maybe MS knows 2.7.1 is needed for Win10 2004 - to avoid the experience reported by Keith?

I too was mystified to find only 2.6.1 on Dell's site.

This IS a real firmware update too.  The usual process/flow and the F2 screen confirms the update.

So I guess these days MS can brick your machine for you if they want to.  Fortunately, the 1 machine is doing fine afterwards.  

One interesting thing about this article is that while the BIOS version for the XPS 8900 is more recent than what is available on Dell support site, the BIOS versions for the XPS 8910 and XPS 8920 are older BIOS versions than those available on the Dell site. For example, the article is dated 7/31/20 and the BIOS version listed for the XPS 8910 is 1.1.10 but the Dell site has version 1.1.11 with a released date of 4/6/20. Also, note that the date for BIOS version 2.7.1 has a release date of Aug. 2020 and the title of that column indicates it is an expected release date hence only the month and year are listed.

I have an XPS 8900 BIOS 2.7.1 running ver 2004 running with no problem, Make a Boot DVD for Windows 10 v2004, boot from it and do a startup repair...
Benny

I had a similar thing happen although my XPS 8900 is still on version 1901 (18363.959) and "still waiting" for the 2004 Upgrade to become available. I did get the prompt to update my BIOS in Windows update and it did update it to 2.7.1 verified on the BIOS splash screen and so far (knock on wood) been running fine.

I'm not sure what 2.7.1 is supposed to address as it is not mentioned on the Dell download site though. MS didn't mention what was new and improved in it either.

Also odd that some XPS8900s did get the update to 2004 and other did not.  I wonder why.

On my XPS8900 the BIOS updated to 2.7.1 but the released date (according to CPUz) is 11/22/2019

So you used the Media Creation Tool and installed from that?  

What is odd to me is I have a Dell 7010 that I picked up at a garage sale for $20. Anyway came with Win 7 Pro which I did the upgrade to Win 10 Pro and that has auto updated to 2004.   This newer box....nope.

very similar thing happened to me:

windows updated itself with a feature update like a week ago to 1904, had no problems with it. Then last night it notified me to that restart was required. I thought it was just an usual windows update. When the computer restarted I realised in a shock that it was performing a BIOS update what I haven't asked for. After the successful BIOS update my new bios was 2.7.1, only problem that it would not boot my system, which never happened before. Been through number of BIOS updates and a few windows feature updates over the years because I got the xps8900 relatively early in the product lifecycle.

I started to investigate and found this topic, but I did not really like the 'solution' here eg to reinstall win10... so I downgraded my BIOS from the boot menu (F12) to version 2.6.1 which is still the latest publicly released version, still have no idea where the heck win10 sucked the BIOS v2.7.1 from...  

After bios 2.6.1 was restored my computer was willing to boot the OS again - or I thought. After an automatic repair It restored the content of the UEFI capsule / BIOS update and updated my bios again to 2.7.1 and consequently would not boot my OS afterwards again... very bad loop especially that I still have no idea where those files are written when w10 prepares to reboot for a BIOS update.

Eventually I managed to boot into the recovery console and tried to uninstall the last quality update with zero luck, got a random error, then I tried to hack my way by removing the pending log, my reward was a different random error message. Eventually I decided to uninstall the last feature update which was surprisingly successful. 

Win10 was thrown back to 18xx but more importantly it no longer wanted to update my firmware to 2.7.1 right away instead of booting the OS itself.

I have disabled the UEFI capsule BIOS update method in the BIOS and updated my win10 to 19xx again with the feature update. It did not try to update my BIOS again, so hopefully this was the first and last time Windows updated my BIOS.

My config is a bit different from the factory one as I have a single SSD sitting in a 4x PCIe adapter because up the m.2 slot on the mobo (1x lane only, quite a bottleneck), no harddrives, but as I mentioned earlier this config was working fine for like 3 years.

I am still unsure if the new 2.7.1 BIOS is broken or MS's way of updating bios is not right or both...

"UEFI capsule BIOS update "

I'd not thought of that.  What an ordeal you had to go through.  I need to find and disable that myself.  But, that's for future MS gimmicks like this.  I already have 1 system pending that's gonna get it as soon as I reboot.  My hope is that like my other 1909 machine that got the 2.7.1 update it will just "work".  THEN I'll lock the door.

If I'm going to try my hand at Russian roulette with a BIOS update, "I" want to be the one that decides that I'm willing to take the risk.  Not MS !!!

@RoHe The service manual for the XPS 8900 does not list its BIOS settings but I do not see a BIOS setting to disable UEFI Capsule Firmware updates in the XPS 8910, 8920, or 8930.