I love Windows 10, its features, speed, ease of use, simplicity, stability, versatility, etc. But sometimes there are some issues, some problems that could literally make you go mad, like the erratic mouse movement.
For me one of those issues was the erratic mouse movement and lags with high processor activity -- around 100%. In these cases the cursor started jumping up and down, left and right, and I simply had to wait for this to be over. Try doing serious mouse-related work on such a computer.
After a long time I discovered what was causing these problems.
The Cause of erratic mouse movement in Windows 10 and Mouse Lags
What was it? At least in my case it was the on-board Realtek sound card and its drivers. Erratic movements and lags mostly started occuring with sound alerts being played, although all the sound goes through the secondary Sound Blaster audio card.
And the solution is...
After your computer starts/restarts enter computer’s BIOS by pressing the ‘Del’ key, or with some computers the ‘F2’ key just after the basic hardware table is displayed by pressing and disable the on-board audio.
And if you want to hear the audio, you’ll need a second audio card, obviously.