My Windows mouse cursor on my work laptop was moving on its own and driving me up the wall. Here’s how I trace the problem and how I fixed it. It turned out the mouse cursor was moving when I pushed the arrow keys. The obscure problem is easy enough to fix, fortunately.
Two things can cause the Windows mouse cursor to move on its own or when you hit the arrow keys. Those are an obscure feature called Mouse Keys, or the venerable Microsoft Paint app.
First of all, this problem only occurs under certain conditions. I had the problem on my work laptop, which uses a second display. I was not able to replicate the problem on a single display system, for whatever that is worth.
It could be related to specific mouse or display drivers, or limited to multi-screen systems. Other mouse oddities, like the disappearing cursor, seem to be. But whatever other things contribute to it, it turns out there are two things that can cause the problem with the mouse cursor moving with the arrow keys in Windows. And you can fix it yourself in minutes. There are only two things you need to check.
Mouse keys cause the Windows mouse cursor to move on its own
Windows has an obscure setting called mouse keys. This was the first I had heard of it, but it allows you to use the arrow keys instead of a mouse if you ever need to do that for any reason. That’s hopefully if you need it, but maddening if it gets turned on accidentally.
To check this obscure setting, press the Windows key or click the Windows logo icon, and then type mouse keys. That will bring up an applet called turn mouse keys on or off. Click that to open it. You’ll see a screen like the one below.
Check the setting labeled control your mouse with a keypad. Make sure that setting is off. If you want to be doubly sure, toggle the setting on and then off.
Microsoft Paint causes the mouse to move with the arrow keys
Believe it or not, the other thing that can cause your windows mouse cursor to move on its own, or to move when you press the arrow keys, is Microsoft Paint. If you have Microsoft Paint running in the background, it can take control of your mouse.
Paint has a useful feature that lets you control the mouse cursor with the arrow keys, to get the cursor in exactly the position that you want. If you want an exact pixel location, it can be very tedious to get to that exact spot with your mouse. Getting into the general location with the mouse and then using the arrow keys to get the exact spot is extremely helpful, and I wish I had known about that trick years ago.
But the problem is, if you have paint running in the background and you are doing something else, Paint can still move your mouse cursor around. In my case, I was editing a document in Microsoft word, and using the arrow keys a lot, and the cursor kept moving every time I hit a key. Having a ghost mouse cursor moving around in my peripheral vision was extremely distracting and annoying.
I had Paint open because I had been taking screenshots and using Paint to scribble annotations on the screenshot before pasting it into my document. The solution was to close paint when I was done scribbling on my screenshots. As soon as I closed paint, by mouse cursor stopped moving on its own.
This meant I had to decide between keeping Paint open or relaunching it if I needed it again, but with an SSD, Paint loads in about a second, so that is tolerable.
Making absolutely sure Paint isn’t running
It’s unusual, but sometimes a program can be running in the background and not have a window open. So if your mouse cursor is moving on its own when you hit the arrow keys, and you don’t have mouse keys enabled, and you don’t have paint open, double-check to make sure Paint isn’t open and hiding from you.
Hit Control-Shift-ESC to bring up Task Manager. Click the text that says more details. Then click the column heading labeled name to sort all of the running tasks alphabetically. Scroll down to the letter p, or where the letter p would be, and look for a process called Paint. If you see a process called Paint, right click on it and select end task. After you do that, that ghost Paint process will shut down, and it will no longer be able to grab control of your mouse cursor anymore and annoy you.
And that’s what to do when your Windows mouse cursor moves on its own.