I have an old PS/2 keyboard that I'm connecting to my Win10 computer via a PS/2-USB adapter. Problem is that it randomly decides to start repeating a given letter as though it's pressed. The only way to stop the repetition is to press some other key. But then the mouse (which I connect through wireless USB) buttons behave oddly (clicking on Chrome tabs causes them to close). To get the mouse back to normal I then have to do Ctrl+Alt+Del.
I can't replicate this problem, it happens randomly.
I don't have any computers taking PS/2 input at home, so I can't test whether the keyboard itself is the problem, or if its the adapter.
Here is the brand of the keyboard:
.
There seems to be no evidence that this brand even exists online, but maybe it's because I couldn't type in the Korean characters.