# [SOLVED] Out of nowhere, now get &quot;BIOS not fully ACPI compliant&quot; blue screen



## Mike Chambers (May 6, 2013)

*[SOLVED] Out of nowhere, now get &quot;BIOS not fully ACPI compliant&quot; blue screen*

I am not a novice with computers. I've been programming and repairing PCs since the 1980s, but this one has got me stumped. It's the craziest thing I've ever seen.

The computer is a pretty old HP Pavilion 8660C. It's got a 533 MHz Pentium 3. Yes, I know this this is pre-historic. I was just doing this for kicks, to see how well it could handle Windows 7.

A few days ago, I put a 160 GB hard drive in it, wiped it and installed a fresh copy of Windows 7 Ultimate. It worked absolutely perfectly for 2 days. Then last night, I found an extra 256 MB PC-133 SDRAM stick in a box of old parts I have. I used it to bump up the RAM in the Pavilion from 384 MB to 512 MB.

I turned the machine back on, at first it seems all is fine. It POSTed, registered all 512 MB of RAM... and in the middle of booting back into Windows, CRASH! It gives me a blue screen of death. STOP 0x000000A5.

"The BIOS in this system is not fully ACPI compliant. Please contact your vender for an updated BIOS."

:banghead:


As far as I know, there is nothing about changing RAM size that could possibly break the ACPI compatibility of a BIOS. Even so, I shut it down again, and put the previous stick of RAM back on the motherboard. At this point it's the exact same configuration as before, when Windows 7 was running fine on it for 2 days.

Turned it back on, and it STILL crashes with that stop error! At this point I think, well the BIOS is from 1999. Maybe there's some intermittent ACPI bug in it. So, I downloaded the most recent BIOS update for the system from HP's site and flashed it. No problems with the flashing, it worked fine. The BIOS is now up-to-date, but it's still s**tting bricks and throwing this blue screen every time I try to boot Windows 7.

Does anybody have any idea what could possibly causing something this issue? I tinkered with various settings in the BIOS, nothing helps. I now have all of the setings identical to what they were before, which Win 7 worked perfectly with until now.

I'm stumped, this makes no sense whatsoever to me. It won't even allow me to boot into the Windows 7 setup DVD, the very same one I used earlier to install and use it on here in the first place. Crashes with the same stop error.

:banghead::banghead::banghead::banghead::banghead:


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## spunk.funk (May 13, 2010)

*Re: Out of nowhere, now get "BIOS not fully ACPI compliant" blue screen*

You should only use RAM that is in matched pairs with the installed RAM. See if this helps: "Stop 0x000000A5 the ACPI BIOS in the system is not fully compliant with the ACPI specification" error message when the computer resumes from hibernation


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## Mike Chambers (May 6, 2013)

*Re: Out of nowhere, now get "BIOS not fully ACPI compliant" blue screen*

Well, the thing is it gives the error even using the exact same two sticks of RAM that I used before that it DID work perfectly with a few days ago. Even if I boot with only one single stick installed, the problem occurs.


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## Mike Chambers (May 6, 2013)

*Re: Out of nowhere, now get "BIOS not fully ACPI compliant" blue screen*

Well, I managed to fix it. The solution makes no sense to me, but hey it works. I'm happy. If anybody else is wondering how I did it, I'll explain. Digging around inside the case, I noticed the floppy drive cable was disconnected on the motherboard end. I guess I accidentally pulled it out when upgrading the RAM. (it's a pretty cramped little case)

This shouldn't affect ACPI compliance, but this is a 14 year old motherboard. Lots of older boards can have strange ACPI quirks. I guess not seeing the floppy drive causes this particular BIOS to create the ACPI tables in a way that Windows 7 didn't like.

But yeah, all is good. Thanks for attempting to help. Maybe somebody will find my solution helps them out in the future. Oh, and Windows 7 (to my utter amazement) runs pretty damn smoothly on that old Pentium 3 with 512 MB RAM installed as long as I don't go nuts with multitasking. I disabled the Windows Defender service, which freed up quite a bit of RAM. It made a big difference.

(disclaimer: don't go and disable your defender service!! i only did because the machine is a dinosaur, and defender eats a lot of resources. but if your machine is not old, the decreased security isn't worth it.)


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## spunk.funk (May 13, 2010)

*Re: [SOLVED] Out of nowhere, now get &quot;BIOS not fully ACPI compliant&quot; blue screen*

The link in post #2 explains you have to delete Hyperfil.sys


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## Mike Chambers (May 6, 2013)

*Re: Out of nowhere, now get "BIOS not fully ACPI compliant" blue screen*



spunk.funk said:


> The link in post #2 explains you have to delete Hyperfil.sys


...

I said I fixed it. It has nothing whatsoever to do with hibernation, which should have been obvious when I said it even happens by simply booting the setup DVD. (booting a setup DVD takes you into a PE environment, so no hibernation)


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