m a bit confused. I am looking to upgrade my computer which has 256mb of ram to 512mb. I had a look on the website that I buy my hardware from and I was quite shocked. There are many different types of 256mb memory modules. They are, PC2700, 3200, 2100 and 133. How do I find out what sort my computer needs if there is any difference at all. My computer has a 1.1 ghz processor, 256mb of memory and Windows XP Pro. If that helps. Thanks.