Here's a follow up question: Is the memory speed a maximum speed for that memory, or must this be specifically matched? I'm assuming that the 200 mhz that my current memory runs at is determined by the chipset on my machine, but I don't find much in the way of new memory rated that slow. Will 400 mhz memory work for me?

Cifara, hi and welcome. There are definitely pitfalls. According to the specs at Dell, your system has a max memory of 2 GB. Anyway, that is plenty for XP and a 32-bit OS can only use slightly more than 3 GB. The 200 MHz number is a clock speed, which is not a measure of memory speed. PC-3200 is the type of memory and that specifies the DIMM type including timings. You may have heard of this memory call DDR400 which is a marketing term. You can learn the basics of memory, DRAM DIMMs and DDR at wikipedia:
http://en.wikipedia.org/wiki/DDR_SDRAM