Have an (2001) HP 750n

have an (2001) HP 750n desktop computer with a nvidia tnt graphics card and I guess the motherboard that goes with it. I lost my internet adapter driver when I reformated. I tried the suggestions that I got yesterday: I went to an hp drivers page, and I downloaded xpsp3. The driver was not fixed in either way. I continued to resear ch the problem and found out that the driver is integrated into the motherboard and the card is attached to the motherboard physically. I have looked for these motherboard drivers but have become frustrated. Can you help me fix this problem