Dear all,?

Greetings, this is ASRock Technical Support Department.

For the models which has this symptom, we have already finished all the BIOS modification.

[COLOR=#00ff00]In addition, d<span style="line-height: 1.4;]ue to Intel limitation,?</span><span style="line-height: 1.4;]t</span><span style="line-height: 1.4;]o support G3258 with Windows 10 configuration, update CPU Microcode is necessary.</span>[/COLOR]

If any further question, please contact us by our official E-mail box :? http://event.asrock.com/tsd.asp" rel="nofollow - http://event.asrock.com/tsd.asp ?

Sorry for the inconvenience. ??

Kindest Regards,

ASRock TSD?

It is a great news that Asrock is listening to its customers. They know that a satisfied customer will always buy their other products again. For the record, I have a H81M-ITX motherboard.

Thank you Asrock Team.

Thank you ASrock, i have http://www.asrock.com/mb/Intel/Z77%20Extreme11/" rel="nofollow - Z77 Extreme 11 please get me new bios for this.

Please flash the BIOS to P1.80 as the link:

Thnx to http://www.sevenforums.com/windows-updates-activation/373250-recent-windows-update-kb3064209-causes-windows-7-not-boot-5.html" rel="nofollow - Cetus35 . 

"Hi all,
I've found a 'solution' (until Intel and Microsoft get off their a** and fix it) and it's amazingly simple, no registry editing, waiting for a BIOS update, changing Windows settings to try to disable the core for a second then re-enable it, or anything. 
It's simply changing the name of a single file. Hard to believe but true.
I not only re-enabled the 2nd CPU core (now I have both, as it should be) but I re-applied my overclock and have experienced no problems whatsoever. 
It appeared that the only way most G3258 CPU owners were getting Windows 10 to install were either disabling 1 core in the BIOS or removing all overclocking settings (using 3.20GHz with Adaptive voltage (all stock, in other words)) or both.
Here's how to fix the problem for now:
1) Either disable one core of the CPU in the BIOS or remove all OC and return to stock settings or both. Whatever it takes to install Windows 10 successfully.
2) Once booted into Windows 10, navigate to C:\Windows\System32 and find the file named 'mcupdate_GenuineIntel.dll'.
3) All you have to do is rename it. Most posts I've read say it's safe to just delete it but I prefer renaming it. Just add .old or .bak to the end of the filename. 
So it would look like 'mcupdate_GenuineIntel.dll.OLD' or 'mcupdate_GenuineIntel.dll.BAK' (or 'mcupdate_GenuineIntel.dll.MyStupidCat' will also work  )
4) You will have to temporarily change permissions on the file to change the name since it's a system file and will say 'File Access Denied' when you try to rename it (or do anything with it, really)
Change the permissions:
(Credit: © 2015 Sergey Tkachenko at WinAero.com)
There are pictures on that site if you prefer to go there and do it that way, but I'll just describe it with steps.
This may seem like a lot of steps but it's necessary for someone who has no previous experience working with file permissions. For those who are, just set permissions as usual to allow renaming of the specified file.
1) Right-click on the file whose permissions you wish to change ('mcupdate_GenuineIntel.dll', in this case)
2) Select Properties then click on the Security tab.
3) Click on the Advanced button. A window named 'Advanced Security Settings for Data' will open.
4) Here you need to change the Owner of the file. Initially it should say the Owner is 'TrustedInstaller'.
5) Click the blue letters just to the right of that that says 'Change'.
6) A small window named 'Select User or Group' will open.
7) You will need to select a User or Group. There are a couple of ways to do this and this step may cause some confusion but here's how I do it: 
a) Type your name or whatever the name is of the current user (click the Start button at the very lower left of the Desktop and the name is at the very top of the left column) into the box that is named 'Enter the object name to select'. The spelling must be exact.
b) Click on the Check Names button. It should then show the name of your computer plus the name you just entered.
c) Click OK.
8) Now you will provide yourself full access to the file. (which will allow the renaming of the file without the Access Denied message)
9) Close all the remaining open dialog boxes by clicking OK on each of them.
10) Right-click the file (mcupdate_GenuineIntel.dll) once more. Select Properties then click on the Security tab.
11) Click the Add button and the box from before named 'Permission Entry for Data' will open.
12) Click on the blue letters that say 'Select a Principal'. Once again the small Select User or Group box will open.
13) Again type in your name or the name of the current user (same as before) and click Check Names then OK.
14) This will take you back to the box named 'Permission Entry for Data'. 
15) Make sure there is a check mark in Full Control then click OK and OK again to close all open dialog boxes.
You can now rename the file.
After renaming it, reboot the computer and enter the BIOS to re-enable the CPU core that was disabled which allowed the installation of Windows 10. 
You can now also re-apply any overclocking settings that you wish if you do so inside the BIOS. I prefer this method but it's not necessary at this time if you use a utility such as Intel XTU (Intel Extreme Overclocking Utility) to set overclock settings from within Windows.
That's it. 
Windows 10 will now boot normally with both cores of the G3258 CPU enabled and any overclocking you wish to add".

MacikaG wrote: Thank you for the new BIOS for my B85M Pro4. Is there any chance later to overclock the CPU under win10? /on my computer the solution above is not working. win10 wasn't installed despite only 1 core. Boot loop remains until I upgrade to the new BIOS./

According to parsec in the http://forum.asrock.com/forum_posts.asp?TID=607&title=oc-tweaker-screen" rel="nofollow - OC Tweaker Screen topic,

parsec wrote: camomatt wrote: Is it possible that they'll update the BIOS to enable Non-Z overclocking again? Or are we stuck with the choices of reverting to an old version of Windows or going without the OC? There is zero chance of that happening, sorry to say. Intel took their battle against this to Microsoft, which helped them win the war it seems.

Now I fixed my problem (and will be updating my post in the topic), but it involved me going back to BIOS version 2.10 and renaming the file mentioned above.

First I changed the file name (I already had Windows 10 installed and no changes to my CPU settings). Then I ran the Windows executable for the 2.10 BIOS update. I rebooted the computer, entered Windows, and edited my OC settings in A-Tuner.

"Hi all,
I've found a 'solution' (until Intel and Microsoft get off their a** and fix it) and it's amazingly simple, no registry editing, waiting for a BIOS update, changing Windows settings to try to disable the core for a second then re-enable it, or anything. 
It's simply changing the name of a single file. Hard to believe but true.
I not only re-enabled the 2nd CPU core (now I have both, as it should be) but I re-applied my overclock and have experienced no problems whatsoever. 
It appeared that the only way most G3258 CPU owners were getting Windows 10 to install were either disabling 1 core in the BIOS or removing all overclocking settings (using 3.20GHz with Adaptive voltage (all stock, in other words)) or both.
Here's how to fix the problem for now:
1) Either disable one core of the CPU in the BIOS or remove all OC and return to stock settings or both. Whatever it takes to install Windows 10 successfully.
2) Once booted into Windows 10, navigate to C:\Windows\System32 and find the file named 'mcupdate_GenuineIntel.dll'.
3) All you have to do is rename it. Most posts I've read say it's safe to just delete it but I prefer renaming it. Just add .old or .bak to the end of the filename. 
So it would look like 'mcupdate_GenuineIntel.dll.OLD' or 'mcupdate_GenuineIntel.dll.BAK' (or 'mcupdate_GenuineIntel.dll.MyStupidCat' will also work  )
4) You will have to temporarily change permissions on the file to change the name since it's a system file and will say 'File Access Denied' when you try to rename it (or do anything with it, really)
Change the permissions:
(Credit: © 2015 Sergey Tkachenko at WinAero.com)
There are pictures on that site if you prefer to go there and do it that way, but I'll just describe it with steps.
This may seem like a lot of steps but it's necessary for someone who has no previous experience working with file permissions. For those who are, just set permissions as usual to allow renaming of the specified file.
1) Right-click on the file whose permissions you wish to change ('mcupdate_GenuineIntel.dll', in this case)
2) Select Properties then click on the Security tab.
3) Click on the Advanced button. A window named 'Advanced Security Settings for Data' will open.
4) Here you need to change the Owner of the file. Initially it should say the Owner is 'TrustedInstaller'.
5) Click the blue letters just to the right of that that says 'Change'.
6) A small window named 'Select User or Group' will open.
7) You will need to select a User or Group. There are a couple of ways to do this and this step may cause some confusion but here's how I do it: 
a) Type your name or whatever the name is of the current user (click the Start button at the very lower left of the Desktop and the name is at the very top of the left column) into the box that is named 'Enter the object name to select'. The spelling must be exact.
b) Click on the Check Names button. It should then show the name of your computer plus the name you just entered.
c) Click OK.
8) Now you will provide yourself full access to the file. (which will allow the renaming of the file without the Access Denied message)
9) Close all the remaining open dialog boxes by clicking OK on each of them.
10) Right-click the file (mcupdate_GenuineIntel.dll) once more. Select Properties then click on the Security tab.
11) Click the Add button and the box from before named 'Permission Entry for Data' will open.
12) Click on the blue letters that say 'Select a Principal'. Once again the small Select User or Group box will open.
13) Again type in your name or the name of the current user (same as before) and click Check Names then OK.
14) This will take you back to the box named 'Permission Entry for Data'. 
15) Make sure there is a check mark in Full Control then click OK and OK again to close all open dialog boxes.
You can now rename the file.
After renaming it, reboot the computer and enter the BIOS to re-enable the CPU core that was disabled which allowed the installation of Windows 10. 
You can now also re-apply any overclocking settings that you wish if you do so inside the BIOS. I prefer this method but it's not necessary at this time if you use a utility such as Intel XTU (Intel Extreme Overclocking Utility) to set overclock settings from within Windows.
That's it. 
Windows 10 will now boot normally with both cores of the G3258 CPU enabled and any overclocking you wish to add".

Can confirm this works very well on B85M BTC. Currently running Windows 10 on Bios 1.50. G3258 Oc'd to 4.2 @ 1.150v. I suggest anyone who tries this to look very closely at which Windows updates are being installed. To make sure MS doesn't patch this.