The system firmware has changed the processor's memory type range registers (MTRRs) across a sleep state transition (S4). This can result in reduced resume performance.

And I have uninstalled and reinstall the display driver, running as admin, but despite repeated attempted, I could not do so in compatibility for W/7 or 8. It would halt at about 75%.  It did install without  compatibility.

I guess what you are saying here is that you still have the error 137 showing up in your event log?

Your first post indicates to me you have tried hard to find a fix for this error, and have gone to non MS support sites in hope of an answer.

This Thread is now 10 months old. If one follows other MS Community Forum threads on this same error event, one will find multiple MS-OS users have yet to find a solution or get an answer to the Question at hand from MS Forum staff. Yet the issue returns in many threads from many users seeking an answer to a Question about W8 that goes un-answered by MS staff. One would think that someone on the MS Forum staff could solve the problem, or just say it is a mystery to everyone and no-one knows the answer to the Question. Frustrating.

IF you ever do find "the answer", I hope you will post back here so that others can read your Good News.

thank you

10.24.2013  

I appreciated your comment: "If you Google "The system firmware has changed the processor's memory type range registers' you find this is a common issue, but I have yet to find a  fix I can confirm. "

thank you

10.25.2013

And I have uninstalled and reinstall the display driver, running as admin, but despite repeated attempted, I could not do so in compatibility for W/7 or 8. It would halt at about 75%.  It did install without  compatibility.

It is an issue, though not a major one, but something is wrong. I have a new PC (thank God), with a Asus 970 extreme 3 mobo, AMD 630 6 core cpu (3.9ghz)   and 8mb ram, and the latest drivers, running W/8.1 and all the necessary updates.  and Fast boot is turned off. But I get this error every time I bring it out of sleep.  

Event 137

Another poster at a different site states:

Technically saving register data, going to sleep, and then coming back and finding something underneath Windows has changed something is definitely an error, especially if it means the system's performance will suffer until it's fixed. It can also lead to not being able to wake a PC from sleep, so yes, it's an error, not a warning. Note that there could possibly be software drivers installed that can cause this, but it's rare. One thing I've found in my experience with this particular issue is that it generally happens on systems with older UEFI hardware, booted in "legacy" or BIOS compatibility mode. I don't know why this is, but I've yet to see it on a true UEFI installed/booted system. http://www.sysnative.com/forums/windows-8-%7C-windows-rt/6284-win-8-x64-event-viewer-error-mtrrs-across-sleep-state-transition-s4.html#post48825

This Community Forum IS* MS's Customer Support !!!

Attention MS Community Forum leaders:

"We have a Problem".

At least 14 MS users have come here hoping for an answer to a Question. !!

None have received a valid answer.

The "Moderator" of the thread only adds to the confusion by suggesting the thread be close. This suggestion is now removed or deleted; yet the Moderator remains silent.

So far, 14 MS users have checked the 'Me Too' Box confirming they 'had' the same Question.

a Post by Mr. Kumar, a Community Star and MS Support Engineer, neither helps nor helped *no one. Yet it remains his sole response MS Forums users.  One would hope that another MS-C/S person might pick up this thread and provide an answer to the question; or at least add a new perspective.

*The original poster deserves an answer, and I assume may still need an answer. Does he have one?

 If not, then this "Question" and this *Thread should stay 0pen, un-answered, while Pleading for support.

where is MS? !!!"

"I have this problem too!!"

10.11.2013

>I have this Error too. I get it moment I put it to sleep. I've tried clean install win8 many times with different bios and drivers. I've disable hybrid-sleep, hibernate and fastboot. Intel Rapid start isn't enable. Is there a way to diagnose the cause? Anyone with this problem please post your system spec. I also have Event id 13 APCI from time to time.<

I have had this problem of resuming from sleep with a blank screen a few times with a new install of W/8 on a new PC. It also was waking up on its own. What has apparently fixed the later seems to have fixed the former, which is to go to Device Manager (Windows key + Pause/Break and look left) and click on Network Adapters and then r. click on your adapter (like Realtek), hit Properties, and under Power management deselect  Allow this device to wake the computer. And select Allow the computer to turn off this device...

I still get the error message (The system firmware has changed the processor's memory type range....), both for S4 and S5, but it has been sleeping and resuming fine.

Hope it helps.