Optiplex gift. Cannot internet does ping as connected.

Hello,
I have optiplex 330 with sticker. Has vista sticker and key that was gifted to me.
Is however running xp.
Works, will ping address all four as connected. However will not make internet work. Times out as cannot connect to anything.
The machine is excellent and so quiet. I could really like it.
I do not know what to do.
Willing to go back to vista.. Stuck.
Ideas??