Does anyone know if there is a patch or fix to remove the 3gb limit for RAM in window3s XP?

My new machine has a tasty 8 gig but due to XP's way of doing things, it only recognises 3gb

And before you say its a hardware issue, not it is not - BIOS recognises the full 8 gig and it is definately a windows XP issue.

Thanking you