installed 2 sticks of ram but only one reads?

[TDiddy]

have a 2.8p4 sony vaio v series it came w/ 1 stick of 512, i took it out and put 2 sticks dual channell kingston value ram and at first it read 1 gig now it when right clicking properties on "my computer" it says 512??

 

[edro]

What does the BIOS say it has? More than likely, the BIOS has a setting enabling more than 512mb RAM. Are they both the exact same model and everything?

Try a program that shows your total physical memory, like Sisoft Sandra or something. Don't trust what Windows says.