I own a Dell Dimension 4600 series. I have an Intel 4 Processor at 2.4GHz and my memory is 512MB DDR SDRAM at 333 MHz. My PC has slowed a little bit since I upgraded my Greeting card software and added a new printer. I am still using windows XP 2002 version. Would I be able to add 1 Gigabyte DDR2 memory for my PC? Thanks.