Ram show up as 1GB in windows But i got 2GB Dual-channel Memory and BIOS show as 2GB

[jambo]

hello

here my system spec's

AMD Athlon 64 FX57 2.8 ghz
OCZ 2GB PC4000 EL DDR Gold Memory
Asrock 939Dual-SATA2
NVIDIA GeForce 6600 512MB PCI-E
hard drives
80GB IDE Maxtor windows xp
200GB SATA Seagate more space
300GB IDE Maxtor more space

so the probe i have is that it only show up that i have 1GB of ram when i go to Control Panel then system i have put each 1GB ram stick in by 1 by on its own and try them in each DIMM slot each 1 on it own and both work fine and been geting some BSOD at random and dont know to fix and can't get my Ram timimg right i set it to what it said on the ram when im in xp i Use CPU-Z and find the speed my ram is running on it is 133mhz should be runing at 200mhz thats what i have tried so i hope there is away to fix this.

thanks

 

[DR.Death]

try prime 95 and see if it is a bad kit