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HP Recommended
Microsoft Windows 10 (64-bit)

Hi! I posted a discussion previously on the HP Z820 boot issue when upgraded to the latest WIndows 10 update:


Solved: HP Z820 on Windows 10 20H2 update. - HP Support Community - 7976870


I thought that the issue was already resolved by updating the BIOS firmware and disabling the Windows update (means PC will stay in older version of Windows 10).


Though I observed that staying in older version of windows 10 works, Personally I can't resist to update it in newer version/build, I tried to halt updates for quite some time waiting the version/build to be stable.


My Z820 has 2 Intel Xeon E5-2670 processor with 128 GB of RAM, I updated it to the latest and stable version of Windows 10 and successfully updated the BIOS firmware .  


Now here's the big issue and the experiments that I've done:



a. The PC is stuck in Windows boot screen.

b. The hard drive lights will blink (indicating its reading) for a while then stop blinking as if it does not read anything.

c. The numlock light in the keyboard turns off after the HDD light indicator stops.

d. Tried to do startup repair but still not working.



In my previous post I observed that there is a difference in the response when I tried to change the Active Processor Core of the PC.

a. CASE 1: Setting the Active Processor Core to ALL, in this setting, all processor cores are enabled, the OS response will be sometimes it will not stuck in the Windows boot screen but most of the time it will stuck.

b. CASE 2: Setting the Active Processor Core to 2, in this setting only 2 cores will be enabled per processor giving a total of 4 cores, the OS response will be normal and most of the time works and will not stuck in the Windows boot screen.


Now another observation that I have is, when I set the Active Processor Core to ALL and it does not work (stuck in Windows boot screen), I will revert the Active Processor Core to 2 and allow the PC to boot, once it successfully boots to Windows, I will restart the PC and revert back again the Active Processor Core  to ALL, in this method all the cores are enabled and the PC will successfully boot to Windows.



I  am now doing a trial and error in this PC:

a. Will try to change the SSD where the OS is installed

b. Turn off the Fast Start-Up feature (I don't know if older HP Z workstations  really supports this feature) 


Its very uncanny to experience this kind of problem, that's why if somebody also has experience in this kind of issue with your Z820 or other old Z Workstation, I would like to hear from you, what did you do to fix this issue?


Thanks in advance!

HP Recommended

Take a "spare" disk-drive, and connect it into your computer.

Disconnect your "production" disk-drive.

Disconnect any Ethernet cable from your computer.

Install Windows onto this disk-drive.

Without the Ethernet cable, Windows Update will not run, and Windows cannot "activate".

But, does this copy of Windows run correctly when "all" processors are enabled?


HP Recommended

Hi @Itsmyname, thanks for that suggestion, I was going to do that method of replacing the disk-drive. Currently I am doing the method of turning off the fast boot option in Windows, and seems the PC boots perfectly.


With regards of re installing Windows without internet I think it will still update the Windows once it was connected to internet, updates can be turned off manually.

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