Mouse jumping around/ moving on its own

Today I was playing a game, Endless Legend, when my mouse started zooming in and out really quickly. At first I thought it was just me touching the trackpad accidentally, but it carried on even when I wasn't touching the PC. I even unplugged my physical mouse and the problem continued. Later on I checked, and my trackpad had been disabled the entire time.

Eventually I deleted my mouse drivers for the trackpad and the physical mouse, updated windows, and restarted the computer.

Now the problem is much better, but still remains in a slightly different form - the cursor jumps around and moves slightly upwards almost constantly. Before it was a problem with the scroll, now the cursor itself is moving.

I fired up Endless Legend again and noticed that the jumping was more intense while I was playing. When I closed the game down the cursor stopped moving and is now (almost) completely still.

Really strange. Does anyone have any ideas about this one?

Thanks, but I gave it a wipe. the problem is still happening

It gets worse when I am playing a game. It will start normally and then gradually get worse over half an hour or so.

While I am watching movies or using the internet its not a problem.