hi there...so here's my problem..i have a HP Compaq CQ58, it has 4 gb of ram (bought new with that)...in the last month my laptop became extremly slower than usual, so i checked the amount of ram i have..it says there that i have 4 gb of ram, next to that it says 929 mb usable...what hapend to the other 3 gb? how can i fix this? thanks