Compaq DC5800 WIndows 11 Issue

[DJK53]

I have a DC5800 on which, by using Rufus, I managed to load W11 22H1 sometime ago.

I have come to try and update this machine in the same way with W11 24H2 and it's telling me its incompatible, having done all the same compatibility work round in Rufus that I did last time.

I am using the same W11 Rufus build that I used to update my two Pavilion 500's so know the build works.

Would anyone have any ideas as to where the problem may be.

It's just a spare PC that sits under the desk so not a real issue I just don't want to be beaten.

[BeemerBiker · Accepted solution]

Windows 11 24H2 is incompatible with certain CPUs, particularly older processors that do not support the "SSE4.2" instruction set, meaning if your CPU lacks this feature, you will not be able to install or run Windows 11 24H2 on your system; essentially blocking older CPUs from upgrading to this version

That being said, it is likely there are hackers looking at bypassing that restriction.

List of CPUs are here

https://images10.newegg.com/UploadFilesForNewegg/itemintelligence/HP/12863_ca1400297343039.pdf

replace the motherboard

[DJK53]

Thanks for the help. From a quick search it looks like a processor swap to something like the Intel Core 2 Quad Q9650 might work. Thanks again

[Paul_Tikkanen]

Hi, @DJK53 

No Intel Core 2 Duo or Core 2 Quad processors support SSE4.2, only SSE4.1

Intel Core 2 Quad Q9650 Specs | TechPowerUp CPU Database

The oldest Intel processors that support SSE4.2 are the 1st generation core processors.

Even the Pentium processors used in the 1st Gen core motherboards don't have SSE4.2.

If you do a search for any Intel 1st Gen core processor, you will see the SSE4.2 spec.

Here's the i5-660 for example:

Intel® Core™ i5-660 Processor

If you can find a W11 23H2 ISO file to run Rufus with, that will work for your dc5800.

[DJK53]

Paul, many thanks. Saved me going down a rabbit hole. 

I did look for a 22h2 iso but couldn't find it. 

Looks like it may be Unix now to keep it going, or finally commit it to the deep 

David

[Paul_Tikkanen]

You're very welcome, David:

You can get one from this link if you want.

Download Windows 11 23H2 ISO images (direct download links)

[DJK53]

Paul, thanks again, 

[Paul_Tikkanen]

Anytime. 

[DJK53]

Paul, apologies for yet another question. I read a post somewhere that implied that Intel's software development Emulator could be used to emulate SSE 4.2.  I don't have the knowledge to understand if this would help. To me it sounds like the emulator is loaded post Windows, hence not a feasible option. Any thoughts? David

'

[Paul_Tikkanen]

Hi:

Unfortunately, I have no knowledge regarding that software.

I didn't even know it existed.

The problem is, unless you can have it installed and running when you do the in-place upgrade from an older version of W11, you wouldn't even have the opportunity to try and upgrade.

I have tried both clean installing and in-place upgrading with Rufus on 23H2>24H2 and Microsoft has locked it down hard.

I have been periodically searching for any videos or info on getting W11 24H2 to work on processors that don't support SSE4.2 and have not found anything as of yet.

They all indicate it can't be done.

Use intel SSE4.2 emulator to bypass W11 24H2 processor requirements - Search