Notebook TOSHIBA satellite pro a200 psaf7a , maximum support ram support?



i just purchased it, it’s come with 2 x512mb ram…i’m running windows vista ultimate edition…if i replace it with 2 x 2gb ram, is this ok? as i see on toshiba website it’s say: my notebook support UP TO 4gb (2 x2gb 667mhz)…is any problem may occurs if i use to maximum limit?..because i will use this notebook for video editing…is anyone experience in this? i just confuse because my friend says i should not run 4 gb of rams on windows vista? i’m not sure what make him says that,there must be a reason for it…pls give me an advice 2gb or 4 gb?

thanks to all…