Apple MacBook Pro (15-inch, 2.53 GHz, Mid 2009) - Manual (Page 48)

48 Chapter 3 Boost Your MacBook Pro
Making Sure Your MacBook Pro Recognizes the New Memory
After installing additional memory in your MacBook Pro, check whether the computer
recognizes the new memory.
To check the computer’s memory:
1 Start up your MacBook Pro.
2 When you see the Mac OS X desktop, choose Apple () from the menu bar and then
choose About This Mac.
For a detailed breakdown of the amount of memory installed in your computer, open
System Profiler by clicking More Info, and then click Memory.
If your MacBook Pro doesn’t recognize the memory or doesn’t start up correctly,
confirm that the memory you installed is compatible with your MacBook Pro and that
it is installed correctly by reseating the memory.