Coarse Graphics on Win98

On boot-up one morning, a non-networked PC running Win98SE inexplicably began installing multiple components that had long ago been installed: controllers, printer, keyboard, etc.

Among the numerous bugs we’re working out is very coarse graphics display on its 17-inch KDS monitor. I have installed updated drivers and re-installed the Standard PCI Graphics Adapter (VGA), to no avail. (This adapter was one of the many items the PC re-installed by itself, duplicating the adapter that was already installed; I removed the adapter showing an error.)

Any suggestions on what to try next?