Problem with RAM

#1
I installed win7 professional on lenovo y430. Before win7, i use vista home premium. My laptop has 4GB DDR3. After installing win7 i checked the system properties. It showed me like that " Installed memory(RAM): 4GB(2.99 GB usable).
What's wrong with my laptop? System type is 32 bit.
 


This website is not affiliated, owned, or endorsed by Microsoft Corporation. It is a member of the Microsoft Partner Program.