Hey!
Most of the time when I use my PC, I have an Opera browser open on the side, and on a few occasions I find my mouse not moving anymore.
When this first happened, I tried closing everything using my keyboard to restart my PC and when I Alt+F4-d every instance of the Opera browser I realized that suddenly my mouse started working again.
I wish I could give you any information about how to make this error happen, but sadly I do not have a clue what makes this happen. On a side note: my PC is not a potato.