RAM not operating at a lower speed than it's supposed to

[Joey104]

I have an old gaming rig, that i just recently obtained. The RAM is ddr2-pc2-8500 1066mhz. It says it's only running at 500mhz. I want to correct this and get it running at full speed. Im not sure where to start.

Motherboard: Gigabyte GA-EP35-DS3R (i think)
CPU:intel core 2 duo e8400
Ram: 2gbx4 gskill pc2-8500 (i dont know the exact model.)

 

[Joey104]

Sorry about the title, i meant: RAM operating at a slower speed than its supposed to.