ASUS P5N SLI-E Motherboard not detecting my new 8gb of Ram

[Rebel2401]

For some weird reason, my computer only "uses" 3.3GB of my new 8gb of installed ram. It all seems to be compatible, I can't understand what the problem is...
My motherboard says it allows up to 8gb of PC-6400 ram which is exactly what I have.

One weird thing to note is that initially i incorrectly installed one of the sticks(so it was only 6GB - as was reflected in Everest), but my computer reflected 3.5GB of usable ram(with all 4 sticks(8 GB), it now only allows 3.3GB. Very strange....

Thanks for your help in advance!

Link to my motherboard stats:
http://reviews.cnet.com/motherboards/asus-p5n-e-sli/4507-3049_7-32180849.html

Link to the ram:
http://www.newegg.com/Product/Product.aspx?Item=20-220-279&SortField=0&SummaryType=0&Pagesize=100&PurchaseMark=&SelectedRating=-1&VideoOnlyMark=False&VendorMark=&IsFeedbackTab=true&Keywords=#scrollFullInfo

 

[Rebel2401]

also my windows 7 is 32bit, is that the problem?(does windows 7 32 bit only allow 4gb of ram?)

 

[T_T]

Yes. The 32-bit operating systems can only address up to 4GB of RAM. The amount useable is typically between 3.25GB and 3.5GB. In some rare cases, some users have reported 3.75 GB useable. What you are experiencing is normal.