Quick question. Did you retain the option to revert , when doing the initial upgrade ?

This said, this sounds pretty similar to what one 7820 user reported as issue around 5 / 7 days ago, and in his case using one of those iastor drivers ended bricking the motherboard, practically.

I think Dell support should pitch in openly, not in private, about this issue. There will be quite a few 5/7820 7920 units getting this upgrade, and given the cost of these units, the upgrade should have been first checked by dell itself using test systems.

@mazzinia 

When I upgraded from Windows 10 to 11, after a few unsuccessful reboots, the system automatically rolled back the upgrade returning the Windows 10 version.
However, if the installation is carried out from scratch on the NVME disk, there is nothing to do but reformat and reinstall windows 10.
However, the strangest thing is that on the SATA drive the installation works perfectly. But if I have a computer with two NVME DISKS it makes no sense for me to use a much slower SSD as the boot disk.

ps: Now i am using Windows 10 Pro for Workstations because i reffuse me to use Windows 11 in SSD disk. And even if you are using an SSD disk, windows 11 does not see NVME disks because you simply CANNOT INSTALL VROC DRIVERS or you will get blue screen!

Apparently it's a problem with the Precision line (5820/7820/7920). As Dell is selling new Windows 11 machines they probably changed something on the motherboard which would be unacceptable (like the TDP problem that exists)...

@Flavius Aetius thanks ... at least this confirms that if this kind of issue arises, the system eventually reverts and works normally back on win10 ( honestly I would hate to have to reinstall due to having to add back all the programs. ok that i've a veeam incremental backup.... )

And yes, not being able to boot nor to use the nvme is a deal breaker.

https://www.dell.com/community/Precision-Fixed-Workstations/T7820-windows-11-ssd-in-flexbay-windows-does-not-boot-after/td-p/8137023/jump-to/first-unread-message

check this thread

Honestly I don't think that it's due to something like that. Out of curiosity, are you using the last bios or 

@mazzinia 

It is curious that Dell has been selling Precision Workstations with Windows 11 for months and the same models that were equipped with Windows 10 have problems. Either Dell has modified some internal component or Dell is using specific drivers on these machines and is not making it available to the general public.

About my bios version: 2.14.0 (12/16/2021)

@mazzinia 

Intel® Virtual RAID on CPU (Intel® VROC) and Intel® Rapid Storage Technology Enterprise (Intel® RSTe) Windows* Driver for Intel® Server Boards and Systems  Intel® Chipset are not Dell drivers and are not supported here.

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@Flavius Aetius wrote:

Workstation 5820 using Windows 10 Pro for Workstations and approved for upgrade to Windows 11. My boot disk is NVME disk.

Blue screen due to a problem with "iaStorE.sys" (IRQL NOT LESS OR EQUAL).

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Sounds like a problem with Intel-RST.

Try setting BIOS to UEFI, AHCI, SecureBoot.

Clean install Windows to a completely blank disk. Never install Intel-RST or eRST.

Hello @Flavius Aetius , I received the notice to upgrade to Win 11 but I only want to run as testing so I installed it on a second drive in the flexbay.  I run Win 11 for workstation with NVMe SSD.  Here is the driver I used for installation. Hope this would help.

@Chino de Oro @Tesla1856 

Hi!

I've tried all this options and this specific driver... no one works. I formated my NVME +- 6 times because i tried all differente ways... at the end, Windows 11 only installs in SSD disk. Then i back to Windows 10 and reinstalled all my programs...

Uhm, but chino shown a working upgrade ( or full install, i'm not sure if he started from a cloned win10 boot drive or not ) on the same kind of unit (supposedly).

Maybe you 2 should compare your bios version, cpu , settings ( in general ) and cards installed to find differences ?

I changed my Dell Nvme Micron to Adata (+ fast), but i can try intall from my Micron Nvme...

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@Flavius Aetius wrote:

@Chino de Oro @Tesla1856 

 

I've tried all this options and this specific driver... no one works. I formated my NVME +- 6 times because i tried all differente ways... at the end, Windows 11 only installs in SSD disk. Then i back to Windows 10 and reinstalled all my programs...

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The settings UEFI and AHCI are for normal-type systems. If your particular machine has a specialized RAID-and/or-Disk-Controller, yes ... you have to the load the proper-driver early in the Windows Install.

When having trouble like this, I suggest only connecting the one drive that you wish to be your C-Drive. It should be completely blank and uninitialized (with no existing partitions). You do not format it first. You install Windows to the "Unpartitioned space".

If you have done all that, but Windows Installer can still not even see the disk to install-to, that is a pretty good indication that your particular machine has a specialized RAID or Disk-Controller, and you will need to follow the proper instructions for it (as defined by manufacturer). 

Worth trying... just to take murphy out of the way, sort of