NUM Lock goes on and off by itself in response to unrelated keystrokes

Just got three new Dell PCs - one Precision 3660 Tower and two Optiplex 7000 Towers. Per my orders, all three came with the Dell wireless keyboard and mouse model KM5221W (the box label says KM5221WBKB-US).

On at least two of the PCs and maybe all three, the NUM Lock goes on and off by itself in response to unrelated keystroke combinations. A lot.

For example, CTRL + SHIFT + Esc open Task Manager (correct) but also causes NUM Lock to toggle On or Off (wrong). And many others.

How to fix?

Could it be related to this wireless keyboard? See also my different question at How do Fn Lock on Dell Wireless Keyboard so F1 -F12 keys work normally

Thanks.

Update on this issue -- and I'm the OP.

I've been on the phone with Dell tech support (which I purchased along with my new PCs). One of the knowledgeable techs explained something to me that I hadn't known, but it's not yet a solution to this problem.

If I (or you) have Num Lock on, the number pad on the right part of my keyboard will type numbers. When it is off, some of the keys will position the cursor around the document. (You can see the arrows and "Home" etc. on the number pad.) Well, that's the basic starting point, and I always set my PCs to turn Num Lock on.

However, when I'm in a document with Num Lock on, and I hold down Shift, then the number pad works as if Num Lock is off. (With Shift down, the number keys won't type numbers - they will move the cursor around the same as if Num Lock is off. As soon as I let go of Shift, the number pad works to type numbers.) While I was on the phone with Dell, I tried this in an Excel spreadsheet, and he was 100% correct. That's not at all a problem and is good to know.

The problem I am having is that, in the new PC with new keyboard, every time I hit Shift or the Win key with any other key, I get an immediate warning at the top of my display screen that Num Lock is turning Off or On. Over and over. That's what I need to get rid of - this constant showing me that Num Lock is temporarily off and then back on. It may be accurate, but it is absolutely maddening. Who needs this? How do I get rid of this constant top-of-monitor popup?

Thanks.

I have made progress on this issue, but not from a direct approach.

It seems that the solution to my OTHER issue, about F1 - F12 keys not working unless one also held the Fn key, has helped here as well. See How do Fn Lock on Dell Wireless Keyboard so F1 -F12 keys work normally

To solve the other issue, I typed Fn+Esc to go into "Fn Lock". Since then, sitting at the keyboard (our new wireless keyboards), the constant top-center display warnings about Num Lock Off and On (whenever I hit Shift+something or Win+something) have stopped.

However, if I remote in to the same PC using AnyDesk, the problem continues. But as that is only me and represents 0.1% of the use of the PC, I'll live with it. At least it won't torture our employees.

I scoured Settings to look for anything related and didn't find anything that changes the outcome. My cursory review of the new BIOS didn't find anything either, but I would need to check that again to be confident.

Once again, Dell has done something "extra" that is entirely non-ergonomic with little concern for its small business customer who puts in a lot of work without in-house advanced IT help to make things run well. If Dell is going to inflict top-center screen warnings about something (when these warnings are not Windows standard), Dell should provide an option to turn them off. In this case, that option does not exist.

Very frustrated, and we spent approx. $6,000 on these three new PCs.

And since I don't know what actually helped with the issue, there is a risk it will recur. Please watch this space.

This is the forum I tried to get an answer for you.
I marked that thread "solved" since you found a workaround.