Screen error: Low-Level setup of window failed

Dear all,
I am facing an error that I haven’t been able to find via search engines.
It might be related to the Windows Update I downloaded yesterday.

The Screen-command does not work anymore. And therefore, my experimental scripts are not running:


This gives the error message:
PTB-ERROR[Register Windowclass failed]: Unknown error, Win32 specific.
PTB-ERROR[Low-Level setp of window failed]: The specified gpu + display + gfx-driver combo may not support some requested feature.

Information about my laptop:
PsychtoolboxVersion: 3.0.18 - Flavor: beta - Corresponds to SVN Revision 12412
Windows 10

Intel(R) Core™ i5-8265U CPU @ 1.60GHz 1.80GHz
System: 64-bit-operating system, 64x-based processor
The graphic card driver for Intel(R) UHD Graphics 620 is up-to-date.

Yesterday’s Windows update:
safety update for Microsoft Windows (KB5007186)

Has anyone had the same issue and solved it successfully?
Any ideas what I could try to solve it?

Thanks in advance!


My Windows 10 (21H1 edition) with all updates applied, including the one you mention, works ok’ish on Nvidia and AMD, can’t test this on Intel. So if this would be related to that update, it would be Intel graphics specific. You could try uninstalling that update - there’s a button for that in the Windows update settings → Update history, and see if it helps.

Any further advice from my side would require paid priority support. But the best free advice i can give to anybody is to upgrade to Linux for a more carefree research life. Even more so if you use an Intel graphics chip.

I’m currently doing the yearly compatibility testing with Windows-10 and continually wonder how anybody can endure this shit-show without going bonkers.

Granted, i stress the system way more than most of you during my testing, but even if i only had to endure a fraction of this fragility and “random things not working and then reboot and suddenly it works again, until it randomly doesn’t”, i would go insane. The same is ofc. true for the macOS “experience”.

Best of luck,

Hi Mario,
thank you very much for your fast reply!

It seems I still do not have updated to the Windows 10 (21H1 edition), so that might do the trick.
Uninstalling the last update would be the logical step to take - but someone told me that it could be problematic to uninstall a Windows Update because of possible dependencies of Windows functions. So that might even make it worse…

Regarding the paid priority support, I didn’t know about this until yesterday. I will definitely talk to my lab about it. Thanks for all your hard work and even free advice like this!


That’s always possible on Windows, but as this is the last installed update, not one in the “middle of the stack”, it should be reasonably safe (famous last words), and can be reapplied if it doesn’t help.

The best way out of such troubles is switching to Linux.

I’m baffled how people can still miss this? It is literally everywhere on our website, part of the sticky welcome messages to this forum, displayed after every PTB install and update, and every single time during PTB startup as part of the startup screen – We hoped our cute frog would at least catch the eye and direct some attention to what is displayed there?

Btw. I intend to propose to my boss a drastic price raise for our offerings and billing model soon, and cut down way more on my free services, to incentivize labs more to do the right thing and financially support us by buying the 150 Euro + tax community memberships. If the carrot doesn’t work at all - and so far 11 months in, depressingly and contrary to anything a thousand labs promised us in past surveys, it doesn’t - maybe it is time to shift more towards the stick. Sad, but apparently necessary for > 99.9% of our users. So far we are losing money by offering support, instead of making any. So now is the perfect time to support us a bit, or at least get one of the last cheap offerings for support, if only out of purely selfish reasons.


Updating to Windows 10 (21H1 edition) solves the problem. :slight_smile: