I had the same experience with my socket 754 Athlon 64. Windows 8 is fine, 8.1 and 10 TP are a no go. I've heard the 32-bit variant is fine, though, so you might wanna try that.

Maybe it's a hardware compatibility bug? I don't know of 8.1 needing any special instructions.
8+ needs PAE, SSE, SSE2, and NX.

It would be worth trying the x32 version

It needs CMPXCHG16b, which Windows 8 doesn't

I feel like I might as well just use XP on it if I'm going to use a 32bit OS....

I suppose this sentiment would change if I had only 2GB installed.

Just install the 32-bit version of Windows 8.1 and you'll be good to go.

Im going with "planned obsolescence", buy new computers now please!

I see no good reason for not supporting K8.

I just read an old discussion about the non use of CMPXCHG16b making that instruction a waste of silicon. How about using it with CPUs that support it while still maintaining 64bit builds that dosnt depend on it? You know like other OSes do with many CPU instructions.

Windows 8.1 x86 can use more ram with some tweaking, but the limit is max 4GB per PROCESS, so thats not so bad?
Guide here: http://woshub.com/access-to-more-than-4gb-of- … -windows-8-x86/

You could always just run Linux on it. I'm dual booting Ubuntu 14.04 and Windows XP SP3 on my Socket 939 setup. It's far from being a useless platform. You can do quite a lot of stuff on it and it's a pretty quiet system too.

Scraphoarder wrote:

Windows 8.1 x86 can use more ram with some tweaking, but the limit is max 4GB per PROCESS, so thats not so bad?
Guide here: http://woshub.com/access-to-more-than-4gb-of- … -windows-8-x86/

That trick only really half-works.

Applications need to be PAE aware to benefit from having that enabled.

and if youre lucky, you will enjoy incombatiblities with many older drivers 😀

Maybe there is another catch, if you have no PAE aware Applications, just use the Memory over 3,25Gb as Ramdisk and place your Pagefile on it.
So you can use it with "some overhead"

forums.mydigitallife.info/threads/46840 ... re-checks)
forums.mydigitallife.info/threads/46142 ... NX-Support
http://rghost.net/52814000

Be aware that a windows update can break things so you'll have to repatch.

1W8CPUFeaturePatch
2
3- Click "Remove PAE check" if your CPU doesn't support PAE.
4- If your CPU doesn't support SSE2 or NX (missing PAE support implies missing NX support) click "Remove SSE2 and NX check".
5- To enable support for more than one logical CPU core after patching NX, click "Fix hyper-threading in hal.dll" and "Fix hyper-threading in halmacpi.dll".
6- If you want to get rid of the digital signature warning on boot after applying one of the patches above, click "Remove winload patchguard x86".
7- Click "Remove various CPU feature checks in Windows 8.1 x64" if you want to skip some CPU feature checks (like CMPXCHG16B support) in Windows 8.1 x64.
8- Click "Remove winload patchguard of Windows 8.1 x64" to skip the digital signature warning that appears on boot after applying the Windows 8.1 x64 check.

Evert wrote:

Just install the 32-bit version of Windows 8.1 and you'll be good to go.

Assuming he can afford to pay for 32-bit Windows 8.1. It's not free, you know.

DosFreak wrote:

http://forums.mydigitallife.info/threads/46840-Windows-8-CPU-Feature-Patch-(Bypass-Windows-8-CPU-feature-checks) http://forums.m […]
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forums.mydigitallife.info/threads/46840 ... re-checks)
forums.mydigitallife.info/threads/46142 ... NX-Support
http://rghost.net/52814000

Be aware that a windows update can break things so you'll have to repatch.

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1W8CPUFeaturePatch
2
3- Click "Remove PAE check" if your CPU doesn't support PAE.
4- If your CPU doesn't support SSE2 or NX (missing PAE support implies missing NX support) click "Remove SSE2 and NX check".
5- To enable support for more than one logical CPU core after patching NX, click "Fix hyper-threading in hal.dll" and "Fix hyper-threading in halmacpi.dll".
6- If you want to get rid of the digital signature warning on boot after applying one of the patches above, click "Remove winload patchguard x86".
7- Click "Remove various CPU feature checks in Windows 8.1 x64" if you want to skip some CPU feature checks (like CMPXCHG16B support) in Windows 8.1 x64.
8- Click "Remove winload patchguard of Windows 8.1 x64" to skip the digital signature warning that appears on boot after applying the Windows 8.1 x64 check.

Turning off the CPU feature check doesn't necessarily eliminate the hardware requirement. Just because 8.1 x64 might install with the CPU feature check turned off, it will probably crash as soon as it tries to execute the unsupported instruction.

The instruction isn't only inaccessible to certain CPU's, some motherboard BIOS's don't support the instruction, either.

My two retail Windows 8 copies can be activated both in 32-bit and 64-bit (it even came with both DVDs), and with a little tinkering with a text file in a bootable setup flash drive I can install Windows 8.1 directly. Never tried, though, as I'm not willing to format either machine, specially not to put a 32-bit OS in there.
I wonder, though, would it be possible to "fix" this with a microcode update? Too bad I doubt anyone bothered implementing this instruction in an Athlon 64 mobo, as then this could be replicated elsewhere.

strange, 8.1 should work with the same requirements as 8.0
(8.0 also requires the hacks for older p4 for example)

I have an AM2 A64 working fine with 8.1 x64