It slow so I want to add memory. Do I need to get the same brand or can I go with a different brand. My computer is a compact.please dont make  two threads on the same issue.The kind of RAM you put in your computer depends on what type it is.  You'll first have to know whether it is SDRAM, DDR, DDR2, etc.  If it's a newer computer you can bet it's not SDRAM.  And unless it is top of the line new it's probably not DDR3 either.  Probably DDR or DDR2.  Now whether or not you can mix brands, yes you can, but I wouldn't recommend it.  For me I do it on computers that I use for testing purposes, and most of the time it's fine.  Though if you want reliablity just stay with the same brand NAME of RAM and you should be fine.  On a side note, if the amount of RAM you get is more than you currently have always put the bigger of the two in the first slot, otherwise you could have memory issues LATER.  Not always, but sometimes.  It's just better to be SAFE than sorry.besides reading, it's much better if you TRAVEL to www.crucial.com by yourself and check in the crucial memory advisor tool dropdown box.incase you don't even know what is you motherboard, download everest.
http://www.lavalys.com/products/download.php?ps=UE&lang=enOn that note don't always trust Everest to be accurate - on my system it tells me that my MASTER hd is a 9G 5400rpm when it is actually a 10G 7200rpm! It also tells me that that hd has a 9.8G partition on it which is pretty hard to fit onto a 9G hd!