Can I downgrade the microcode on my Intel CPU?

ZodaEX

Supreme [H]ardness
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Gigabyte recently a released Meltdown and Spectre microcode update for my CPU that came with my Gigabyte GB-BXBT-2807 barebones PC.

Upon installing this microcode update, Windows 7 stopped working. I tried to reinstall Win7 to get it working again, but now that i've updated my CPU's microcode, not even the Windows 7 installer will work.

So my question is, is it possible to downgrade back to the older CPU microcode I was using in order to fix my computer, or can you only update it?
 
Did you do the step after updating which is reset to defaults in the bios?
 
Did you do the step after updating which is reset to defaults in the bios?


Yes I did reset the CMOS defaults 6 times actually because I second guess myself a lot. I've already tried so many things that i'm afraid to even say what i've tried because then folks would see a gigantic wall of text and probably not want to read it and try and help with my issue. That always happens to me on this forum when i'm not brief enough with my problem. Do you happen to know if downgrading an Intel CPU's microcode is possible? I'm also open to any other suggestions. At this point I feel fucked over by Gigabyte corporation. They removed links on their support site that will actually get Linux working on this motherboard, and they won't respond to my support ticket. Unfortunately for me however I really need Windows 7 on this machine, not Win10 or Linux.
 
Looks like the Spectre mitigation worked:

2l4itc.jpg
 
Cant you just try and flash the bios to an older version?


Yes! I have tried to do this actually, and the results were strange to me.

On the latest firmware, I can only get Windows 10 installed out of the 3 operating system's i've tried (Win7, Win10 & Ubuntu).

If I roll the firmware back to any past version, Ubuntu Linux works perfectly fine, however my keyboard and mouse immediately stop working the moment the Windows 7 installer pops up.

From this behavior, along with my experience in troubleshooting PCs over the years I have concluded that microcode updates to Intel CPUs must stay installed even if you revert back to an older bios. This is why i'm now looking at a way to downgrade the CPU's microcode. In all my years of using PCs, this is the first time in my life i've ever messed with microcode so I feel pretty out of my element. I don't know what is possible and what isn't in regards to modifying cpu microcode. I'm just looking for a way to go back to the original microcode that came on the CPU when I first got it since the machine worked perfectly until the microcode and firmware was updated. (firmware has since been downgraded back to the old 2014 version I was previously on.)
 
Maybe hunt for a old bios chip for your mother board? Prob can find them easy on ebay.. and prob not updated.

Other then that have you tried pulling the battery from the motherboard and holding in the power button for like 15-30 seconds.. as that usually a good way of resetting the settings in the cmos just encase it's not resetting.. I even heard of people pulling the battery for 24 hours just to get it to reset.
 
Maybe hunt for a old bios chip for your mother board? Prob can find them easy on ebay.. and prob not updated.

Other then that have you tried pulling the battery from the motherboard and holding in the power button for like 15-30 seconds.. as that usually a good way of resetting the settings in the cmos just encase it's not resetting.. I even heard of people pulling the battery for 24 hours just to get it to reset.

I actually do happen to have a spare bios chip for my motherboard. Is this where the CPU's micro-code is stored? How do you change the bios chip? Do you need any special tools or anything like that? I'll try the trick of removing the CMOS battery for several hours and putting it back in. I haven't tried clearing the CMOS that way yet thanks. It's just so odd to me that Windows 10 and even Ubuntu both work perfectly on it, but not Win7.
 
I actually do happen to have a spare bios chip for my motherboard. Is this where the CPU's micro-code is stored? How do you change the bios chip? Do you need any special tools or anything like that? I'll try the trick of removing the CMOS battery for several hours and putting it back in. I haven't tried clearing the CMOS that way yet thanks. It's just so odd to me that Windows 10 and even Ubuntu both work perfectly on it, but not Win7.

Quite often the bios chip is just in a dip socket and can be easily removed.
 
Well tuff to know forsure what tool you'll need without seeing it.. I'd say prob a small skinny flat head to pry it up but you wouldnt want to scratch anything around or under the chip or crack the socket. Something plastic and strong would be best.
 
I thought the microcode was part of the BIOS? I think it can also be loaded as part of the OS as well.
 
I thought the microcode was part of the BIOS? I think it can also be loaded as part of the OS as well.

I thought so too, but downgrading my BIOS does not enable Win7 to boot or even install, so it appears to me that once microcode is updated, it probably can't be re-downgraded by simply loading an older bios. Downgrading my bios does allow Ubuntu Linux to work so my running theory is that the latest bios isn't Linux compatible, and the latest microcode must not be Win7 compatible. (going by what I have witnessed with this PC's behavior, to be fair though this is the first time in my life messing with cpu microcode)
 
That's why you swap the bios chip and dont flash it to the latest version which changed to the latest CPU code.
 
So, it took Gigabyte almost a year to release BIOS update for Spectre and it came out 'broken'. :D

You're lucky... use this: https://hardforum.com/threads/intel-microcode-boot-loader.1970313/

If the builtin microcode won't work neither, get an older version from: https://downloadcenter.intel.com/download/28087/Linux-Processor-Microcode-Data-File

Oh man wow. Thanks for this! Is it really necessary to have a USB drive plugged in at all times? This PC only has 3 USB ports total and i'm usually using all 3 lol.
 
Oh man wow. Thanks for this! Is it really necessary to have a USB drive plugged in at all times? This PC only has 3 USB ports total and i'm usually using all 3 lol.

You should see if it works first, then worry about that. If your PC doesn’t boot with an old microcode loading, maybe Windows is hosed.
 
Oh man wow. Thanks for this! Is it really necessary to have a USB drive plugged in at all times? This PC only has 3 USB ports total and i'm usually using all 3 lol.

You could host it on a secondary HDD or small partition with adjustments to grub.cfg, but its a matter of time until Gigabyte will release a fixed BIOS for your mobo.

I suspect the BIOS (Gigabyte) is to blame for this. Intel took their time QA all microcodes.
 
You could host it on a secondary HDD or small partition with adjustments to grub.cfg, but its a matter of time until Gigabyte will release a fixed BIOS for your mobo.

This is presuming Gigabyte still cares about Windows 7 support on a niche product...
 
You could host it on a secondary HDD or small partition with adjustments to grub.cfg, but its a matter of time until Gigabyte will release a fixed BIOS for your mobo.

I suspect the BIOS (Gigabyte) is to blame for this. Intel took their time QA all microcodes.

The most recent bios they release for this board was 7 months ago. I wonder how long it usually takes Gigabyte to fix botched updates after they've removed all previous working versions from their support page. I hope not another 7 months. :p :)



Windows 7 may lack support for USB3, NVMe, DirectX 12 and some more. But at least, it doesn't install CANDY CRUSH SAGA without the user's permission. :X

Absolutely. And a big concern of mine is when your on a ultra low power 1.5ghz dual core celeron fanless CPU, forced Windows 10 O.S. upgrades are obviously going to take hours to install and i'd be spending more time waiting for my HTPC to update than I would probably spend watching movies. Not only that, but this APU barely supports Direct X 11, much less having the horsepower to even actually run any DX11 games. My greatest gaming success on this thing has been Left For Dead and 16 bit game emulators. Candy Crush? Barf. Maybe if Windows 10 came with Minecraft included (they own the rights) then I might have been tempted to try it.
 
Absolutely. And a big concern of mine is when your on a ultra low power 1.5ghz dual core celeron fanless CPU, forced Windows 10 O.S. upgrades are obviously going to take hours to install and i'd be spending more time waiting for my HTPC to update than I would probably spend watching movies.

Possibly still less time than trying to fix this though!
 
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