asus m2n 5 gb installed 3 gb used

hello
i have asus m2n motherboard and my problem is: 5gb memory installed,but windows write: 3gb used. in bios is recognizes all memory. what can I do to use all the memory?
the "newest" bios is installed. memory hole remapping enabled.

here is the screenshot

fess said:

here is the screenshot

2GB is hardware reserved most probably for your graphics card
Go to msconfig>boot>advanced options and uncheck maximum memory

Rest all options in your BIOS then re-eanble memory remap

+1GB use :)
i put 2*2GB in the yellow socket(dimm A1,dimm B1) ,and 1gb in the black socket(DIMM A2). is this good?

it's worked. " msconfig>boot>advanced options and uncheck maximum memory" i was deleted from the pipe,reboot,then see all memory
very thank you for your help

fess said:

it's worked. " msconfig>boot>advanced options and uncheck maximum memory" i was deleted from the pipe,reboot,then see all memory
very thank you for your help

Glad I could help :)