Do we have to buy new CPU's if Windows Updates go wrong ?

In the past I have often recovered from a defective update by restoring a Partition Image backup of C:\.

How can one fix a CPU with damaged "processor microcode" ?

KB2818604 - Microcode update for AMD computers (Windows 7 and Windows 8). This update is for computers that use certain AMD processors (C, E, G and Z series) and updates the processor microcode. There is a Fix It link available as well as instructions for manual installation.

http://www.techrepub...-june-2013/7846

http://support.microsoft.com/kb/2818604

I was not even aware that a software update could modify silicon.

Sounds like something just waiting to go completely wrong.

If any disasters ensued, I wonder if they could be "fixed" by using a "Family Processor Microcode Update" from the maker of their hardware to overwrite the errant code from MS?

This is all new to me, but a quick google found this from HP ...

Family Processor Microcode Update:

This is all new to me, but a quick google found this from HP ...

Family Processor Microcode Update:

If Microsoft and HP can modify the Microcode,

what can stop malware from doing mischief to the Microcode ?

At 21:05 G.M.T. this is me wishing all my readers pleasant dreams - or otherwise :o

A software update cannot modify silicon.

Updating the "processor microcode" is akin to firmware updating. So it only changes the upgradeable ROM on (or the chips associated with) the processor (or a piece of the processor that's available to overwriting- by design).

I don't know much about the process, but perhaps the updates are digitally signed by the manufactures (or, by Intel/AMD themselves) which would prevent a fraudulent/malicious microcode installation. Digital signing is virtually impossible to spoof and would require code-espionage and stealthy implementations to avoid detection (upon actually successfully stealing a digital certificate).

Or, perhaps, the microcode update is encrypted by Intel/AMD and the key to decrypt/implement the update only exists on the silicone itself (thus, only Intel/AMD could actually approve of the updates and allow specific updates to be handled).

All of those processors listed in that update are APUs meaning the graphics chip is integrated into the cpu. My guess is that this update is to better integrate the power of that graphics chip into general usage by windows. Basically I think its just a driver update but who really knows except MS.

In many older processors (I never bothered to research the new ones, nor do I care to) the microcode updates are "downloaded" into the processor upon system startup. Every time. Just like loading into RAM.

Either the BIOS feeds the updates or a Windows driver feeds the updates. If something should go wrong, all you need to do is kill the power and start again.

This is new to me. On my old AMD Phenom processor microcode updates came via bios update.

Found this in the list of drivers when using NirSoft's ServiWin:

https://dyp.im/UukPLeQ2JD

So the Processor Microcode is not "patched" upon the installation of the Windows Update,

but instead it is patched by a manually started Service - an "on-demand" patch.

When I first read that Microsoft were patching the processor microcode it brought back unhappy memories of being on training courses,

based on reconfigurable processors such as Inmos Transputers and Xilinx bit-slice Digital Signal Processor Arrays.

I was horrified by the thought that Microsoft could replace the AMD processor instruction for "Divide A by B" with their own enhancement to benefit Windows vs Linux,

and that due to a Microsoft oversight a "Divide by Zero" error would cause a BSOD.

It is a slight comfort that after such a BSOD the system can restart and run again - until the service is again started "on-demand" :wacko:

You learn something new on here every day most days. :)