Can only run 640x480 and 16 colors, why?

[Romial]

I've had some spyware problems that I've fixed now, but now I can't get my computer out of 640x480 screen resolution and 16 colors. Not 16 BIT colors, just regular 16 colors. This computer is 7 years old or so, but it used to run on 800x600 and 16 bit colors, but now whenever I try to apply those changes, it doesn't stay. Anyone know why? It's a 333mhz computer with 3D Blaster Riva TNT graphics card. Anyone able to help me out please?

 

[vnf4ultra]

Video

Did you try updating your video drivers?