PC freezes for split second then resumes with laggier mouse

[Argus]

when I start up my PC, after about 3-4 seconds, everything will freeze and then resume as normal.
During those first 3-4 seconds before the freeze, the mouse feels really good and the screen is nice to look at.
Afterwards, it goes to shit.

EDIT: also wanted to mention that before the freeze, about 2 seconds after starting up, the screen goes black for a split second. EDIT/

I've tried disabling many startup programs and services and tried doing clean installs of windows 10 ltsc but I still get the same issue for some reason. For some reason it doesn't happen on any other PC I use even on bloated laptops that come preinstalled with windows.

Anybody else have this issue? Is there a list of startup services that are safe to disable? I can't think of what else to disable that might be causing this issue.
What could it be?

[InputLagger]

Use this https://learn.microsoft.com/en-us/windo ... exercise-2

[Slender]

i think it virtualization or like that. Try to disable that in bios and reinstall windows.

[ApexLeg]

I had this and realised it was vibranceGUI on automatic start. If you don't have that program running it may be an overlay or something GPU related, best thing to try is to remove startup items one by one.