Question : Problem: problem with NVidia

My display has horizontal lines and bands that should not appear.  Additional lines/bands appear whenever I open an additional window.  The boundaries of the bands seem to coincide with lines of text, boundaries of windows, and/or other "natural" boundaries.   Also, the colors and the overall look and feel of text are different from what they were before this happened.

This is not one of the problems listed in the manual for my monitor (under Troubleshooting), so I suspect it has something to do with the video card (NVidia Vanta (HP - English), Version 4.12.01.0384).

Any suggestion as to what I can do to restore normal display operations?

I see that some experts on EE have suggested that others with video problems try installing a video card on another computer.  I have no other computer on which to do that.

Operating system is Windows 98 Second Edition.

Answer : Problem: problem with NVidia

Yeap. The GUi (Graphical User interface) starts loading when the windows logo appears. Before that it's text mode. Video Card drivers load together with the GUI, so, if the problem appears before the drivers are loaded, you have a failing video card for sure.  This kind of bands are usually due to video memory problems.
If I were you, I'd test the vid card in another computer before trashing it.

Good Luck