If you have issues with today's Window's update (KB5005033)...

[kalniel]

..try switching from your third-party AV to Windows Defender while running the update.

I was repeatedly getting BSOD at 20% install with KB5005033 Cumulative Update for Windows 21H1 - Kmode exception not handled, kernel security check failure etc. which point to more than one application trying to access/overwrite the same bit of memory. I guessed it was probably my AV which runs in a pretty protected way so paused it while turning on Defender and it was all fine.

[CAT-THE-FIFTH]

MS one step forward,two steps back.

[AGTDenton]

Just for reference at what stage did you experience the BSOD, whilst it was in Windows or during the restart phase?
Thanks

[kalniel]

MS one step forward,two steps back.

Not MS in this case, the third-party AV was to blame. Said third party subsequently updated the software last night so perhaps they've fixed it already.

Just for reference at what stage did you experience the BSOD, whilst it was in Windows or during the restart phase?
Thanks

While still in Windows on the settings/update - it would trigger some time after the install hit 20%

[kompukare]

Not MS in this case, the third-party AV was to blame. Said third party subsequently updated the software last night so perhaps they've fixed it already.

Er? So none of Microsoft's test machines had this AV installed?

If none did, Microsoft's internal testing is worthless.

Or they did have it and Microsoft pushed the update regardless.

Either way this is squarely Microsoft's fault.

If it was the first and only time one of their poorly tested updates broke something, I might be more forgiving but since at least Windows 10 these have become increasingly common.

[kalniel]

MS can't be responsible for every bit of third party software out there - go down that route and we'll be locked into only using MS approved apps from a walled store.

But I agree, it should have been picked up by testing since it's not massively obscure.