Hello, i have dell inspiron 5520 i install window7 32bit my ram is 8gb but show only 2.66 gb
Any 32bit operating system only recognizes up to 4GB of RAM. And if you have integrated graphics, it is likely another portion is sealed off just for the graphics.
Open up the start menu and type "resource monitor" and open the program. Go to the Memory tab. It will give a little graphic on how your memory is being utilized.