Hell yeah...!
I dont know, if the MX 440 is the best choice, if u get an upgrade.
But..! There is a HUGE difference between the card.
I used to have a Voodoo 3 2000, and I got a GeForce 2 MX 400 now.
Big difference! So its worth it.
On the other hand. You could get something better with the money. Or something even more better with a little more money... A GeForce 3 doesnt cost that much more, or get a GeForce 4 TI 4200.
Also, your CPU isnt all that fast, so even with the best Graphics Card, there wont be such great results.
If you dont want to get a new CPU and Motherboard, or spend that much money on a GFX card, the GF 4 MX is ok. Otherwise, get something better.