Hello everyone. Before I get to the main problem, I'll explain what happened to my laptop and Krita app. My laptop's hard drive was broken and I got it replaced by a new one, reinstalling Windows 10 on my laptop and all that stuff. Before the drive was replaced, I used Krita and it went smooth and fine, no problems. It was version 4.2.4 if I recall correctly. Then I installed the same version after the drive is replaced, along with my Wacom tablet driver.

I made some brush strokes and sketched for few minutes. Then the problem started; the brush went weird and "skipped" (I don't know how to say it in English I'm sorry) after I made strokes, like in this video: https://drive.google.com/open?id=1TYoI0JSqhMrNn-6XC95LaTsv54MWjfke. If you look closely, the brush skipped some space in the direction of the brush stroke. It gets worse the longer I keep sketching, and I have to close and reopen Krita to fix it. When I first opened the app, the brush didn't do that: https://drive.google.com/open?id=1rWLdSq2Y-2T7Zr0ucKUqp2mHbWHL8mWh. It was smoother.

I reinstalled Krita and my tablet driver few times and nothing changed. I even tried the newest version of my tablet driver, but since my tablet is so old, I decided to get back to the old driver for the tablet. Then the version 4.2.5 of Krita came, and I installed that one, replacing the old 4.2.4 version. But the problem persists. I even checked whether I turned on the brush stabilizer, but no, I didn't. Also I increased RAM usage for Krita, and no change.

I don't know what causes it, whether it's my old tablet, my PC after replacing the hard drive, or something else. Or it's just Krita is no longer compatible with my PC...

Can you try to switch the graphics driver from opengl to angle(or the other way around?), we've had reports that makes a difference with stuttering on windows.

Thank you for the reply. I've tried changing the graphic driver from ANGLE to OpenGL, and the stuttering is still present, although it's slightly lesser than before. https://drive.google.com/open?id=187ld3UynQHgecdxHFd7VaDvym_bYp7lX (sorry for the song).

And if you turn off graphics acceleration?

Oh! Have you tried reducing the double click sensitivity? (Try this before you try my first suggestion)

Okay. I've followed your suggestions. I have reduced the double click sensitivity setting, it didn't fix the problem. The same with turning off graphic driver... The stutters are still there. I recorded it, in case my eyes didn't see it right... https://drive.google.com/open?id=1Dx6j4noAhpaxyWSSsFPWhVlLltpIzWqy

I wonder though ... the guy replacing my hard drive installed a possibly pirated Windows 10, while I previously had an original one from buying the laptop (it's gone along with the broken hard drive). Does that affect the performance?