hey, im looking to upgrade my computer by adding more ram to it but i dont know how much more my motherboard can handle or what type
currently i have:

Motherboard: Machspeed P4M800P-8237

Processor: Intel(R) Pentium(R) D CPU 3.20GHz
clock speed: 3207

Total Memory Detected in Hardware: ~2048 MB
Memory Reported to Operating System: 1023MB

type of ram: Ultra 1024mb PC-4200 533mhz

OS: Windows Vista Ultimate x64-bit

thanks in advance