You might have a program installd on your pc that your computer is always runing, if youe have to many programs running it can cause freezing NOTE on your computer box, just under the power button there should be a red light if its on constantly it means its doing somthink you should wait untill it flashes every 6-7 seconds if not i know your memory is fine but try buying a usb hard drive wich simply plugs in to a usb port, that should speed things up
