my all-in-one pc is unusable until the disk light stops blinking

so annoyed rn ive followed every guide online: disabled SysMain, turned off Search indexing, even uninstalled some apps, still:

Disk 0 (C:)   Active time 100%
Not responding

The all-in-one PC is pegged after opening teh browser :) My patience is gone. Is there a way to actually find out whats using the disk instead of disalbing random services?? Every guide says something different and Im tired of guessing. If someone could show me how to find the real culprit, Ill happily do the work. pls help 🙏