Help upgrading RAM on Dell?

I have a Dell Dimension E310 and I want to upgrade from my puny 256MB. I've been looking at some sites and I found a good price on a DDR2 PC2-5300 1GBx2 memory kit. The problem is when i went to crucial.com it insisted I use a DDR2 PC2-4200 even though my PC can accomodate that or a 5300. My question is how do I know if my PC can handle the speed of the 5300 because I don't want to buy it just to find out it doesn't work or worse yet, crash my computer. also I have a pentium 4 proccessor if that means anything. Thanks in advance for any help.