No, the G860 is a LGA 1155 CPU and that board is Socket 478 (EXTREMELY limiting, as far as upgrade options go).
Here's the supported CPU's list http://www.asus.com/Motherboards/Intel_Socket_478/P4S800MX/#CPUS
but it looks like the best that you can do is a P4 HT 3.4Ghz.
Honestly, it's not worth upgrading that (you'll NEVER be able to play ANY of those games with ANY upgrade that you can do). Time for a completely new system, I'm afraid.
Edit: Took too long to get my info, lol.