Serious bug in Windows

I have noticed a serious bug in Windows. It's happened before but I didn't know why. Now I think I do! This happened today on all three of our machines. All were left on a while, idle enough time for Windows defender to do some kind of background auto scan. After I went to Windows update to check for updates, and each one took ages checking. It took minutes to report back none available and the time was out on the last check timestamp, it was several minutes before it really had finished. Weird and then I noticed high cpu usage and saw it was Windows module installer (which relates to Windows update). Frustrated it wouldn't calm down I restarted each machine one by one and in every case rather than restart it got stuck on 'Windows is busy configuring updates - do not turn off' (or something to that effect). Even though there were none to install! This screen stayed like this not changing, so after about 20 mins I force shutdown each machine. After rebooting each one all was fine again. But I am convinced Windows defender is too blame in each scenario. Normally our machines aren't idle too long enough for defender to do automatic stuff, any scans I do are manual. But today they all got to do it and all got met by this problem. Makes one reluctant to let the PC idle for any significant time for fear of this side effect.

i don't know how often defender performs auto scan checks if a machine is left idle. Every 24 hours? But I certainly don't want it doing auto checks if this is the side effect if one decides to do a windows update check afterwards.

like I say I have encountered the phantom configuring windows updates before and never actually restarting (albeit pretty rare) across different windows 10 machines and different builds/versions. It always made me wonder if Windows update was bugged at the time but now I think it's the combo of defender and Windows update at the heart of the problem. It's a concern because I certainly do not like force shutting off machines in such a manner

obviously I keen to find out if others have noticed same anomalies over the tenure of Windows 10. Maybe it's hard to recreate, my penchant for regularly checking for updates may mean I notice this before many ever would

I have to ask..... Have you shut down all the massive security holes in Windows 10?
Like WUDO? If not, you DO need to kill that monster immediately.

Don't know what I'm talking about or how to go about it? Well just google "Kill WUDO" and you will find out the How and Why of it.

You can also disable the service "Windows Update" and Windows Defender will still be able to get it's updates.

I don't know how anyone can run Windows 10 as it comes from MS. It's so full of security holes, it's a nightmare.
On a clean install, I always use the "Custom Install" method to turn off all the CRAP that I don't want running in the background,
and when I have to work on a Windows 10 PC that's already installed it takes a while to go through all the menus and disable all the stuff that should NEVER be left running in the background.

So, if you're running Win-10 as it came from MS, I can understand why you're having problems.

Good Luck!
TechnoMage