Increase fps by getting directx 7 if possible?

hey all, i was woundering if i could download directx 7 anywhere if possible instead of my directx 9. Reason being beacuse i played the new cod2 demo and when it said enforce directx 7 i got more fps when i enforced it. Is there anyway of getting rid of directx 9 and getting directx 7? i checked everywhere and i cannot seem to find it. and will it harm my computer in anyway if i do degrade versions? thnx- bl1nked

Hi
I don't think xp will allow one to run a dx ver below 8.