Hi:

Try to lower the resolution or install different drivers.

this kind of glitches appears with faulty ram modules on the graphics card, bad connection on the PCI/ISA slot,
PCI with weird clock/noise signals.

Regards!

PD: it's that WinME? 🤐

Looks like my lot of old Trio64+ cards, whose caps have been dying over the last few years.
If the cards are worth the effort, just try recapping.
But keep in mind that bad caps on MB and PSU can also produce this effect.

My S3 produces similar artifacts, but not always. Perhaps it's not properly plugged into the PCI slot, DSUB connection issues...

Check the legs for any bent pins making contacts. Probably time to recap it though.