Hello!
A power of two texture refers to texture images used in the game or program being run. Examples of this would be image sizes of 16x16 pixels, 32x32, 64x64, 128x128, 256x256.....2048x2048....
Apparently whatever you are trying to run contains textures that are not of these sizes. Non-power of two would be 1020x960, 129x129, 53x195, etc.
Your video card is very old (2003 I think) so it sounds like it can't handle these and doesn't support direct3d9.
I think you need a newer video card. Any cheap modern card will do.