Memory upgrade problems

I just bought some new memory for my computer and installed it. The problems is, when i check my system information in the controll panel it still reads the same as it did before i installed the new ram. I had 4gb of ram before the new purchase and i was trying upgrade to 8gb of ram, but it only reads 3.25gb. It said the same thing for when i only had 4gb. But if i go to the start button then click accessories , the click system tools and then system information it shows, total physical memory @8192.00mb and avalible phys. memory @2.73 gb, total virtual memory @2.00gb and avalible virtual memory @1.96gb, thats with all 8gbs of ram installed. But if i remove the 2 new cards the only thing that changes is the total physical memory to 4096.00mb and the rest stays the same. Is there something wrong with my cards even though there not made by the same company? And how come it only reads 3.25gb on the system information in the controll panel not 7.25gbs?

 

Since you didn't say what OS you are using my first guess would be it's probably because you're running (corrected to read) a 32 bit OS, which has a physical memory limit of 4GB which typicall translates to a 3.25GB usable limit.

 

Thanks, for responding. I am using windows xp professional. Someone told me i should upgrade to a 64 bit version, like vista. Is that true, or what do you recommend?

 

Implied but not stated correctly.

Thanks for the catch.

@Mike. DDP, as usual has gotten it right.

 

Or just get windows 7 now, and use it free for a year!