OCZ memory?

Perhaps you could tell us what model number Dell you have. The memory you linked to is designed for notebook computers and won't work on desktops. It's also important to verify that you are ordering the correct type of memory (for example DDR vs. DDR2). Upgrading the memory yourself won't void the warranty, unless you damage the computer in the process (which should not happen if you're careful and don't force anything).
 
Sorry, my laptop is a dell E1505 Core 2 duo processor 2.0ghz with 4mb cache and 667mhz fsb, x1400 mobility card, and its ddr2.
 
Playing WoW i get good gameplay but i notice it hogs alot of my memory (already knew that) and i just wanted more for good measure?
 
Playing WoW i get good gameplay but i notice it hogs alot of my memory (already knew that) and i just wanted more for good measure?

Try this: Close all programs, return to the windows desktop, and press ctrl-alt-delete. How many processes are running? How much RAM is available?
 
OK, looks like that RAM should work. However, there are some potential performance issues:
1) The rate at which info flows to/from RAM is doubled if the system can run in "dual channel" mode, which requires a *pair* of modules of the same capacity , organization, timings, and speed. Usually, it's easiest just to install a pair of identical modules. What size/speed/latency module(s) are currently installed in the computer? There's always the possibility of removing the module(s) currently installed, installing a pair of identical modules, and selling the old modules on eBay.
2) The latency timings on the RAM you linked are pretty slow (CL 5). However, this would only result in a few-percent drop in performance, unlike issue 1.
 
A core Duo has an FSB of only 667 Mhz I believe

Sooooo upgrading to higher mhz ram from the 533 will not speed much up, because the fsb will choke fast ram, you should be looking for ram with a lower cas latency.

But honestly the lag you experience most likely is not ram related. If you have ram left over while running wow. You should try to clean up bloatware. But for the most part laptops just aren't great gaming platforms. an x1400 mobility just isn't very fast. Try reducing resolution and turning down the visual quality.