misreporting RAM size

i have tried to find an answer on google to this and it is not looking for what i am asking , i have a computer with a k8m800 MB it had 2 512 dimms in so in the computer properties it should be reporting 1 gb of ram but is reporting 8gb after being told it could be faulty mem modules i installed 2 1gb modules pc 3200 and that is reporting i have 16gb the os is vista ultimate , i have reinstalled the os and it is still saying i have 16gb of installed ram and is now doing 167 updates , can anyone tell me what is causing this problem the effects it will have and how to cure it hopefully ? or should i just junk it ! i am using the on-board graphics if that helps

Check in the BIOS for the reported memory size. Press F2 or DEL when the computer is starting up to get into the BIOS.

Alternatively, run the System Scanner at www.crucial.com and see what that reports.