Please help me

[jobj17]

I dont know much about computers. but I need someones help.

my computer:
AMD Athlon XP 2200+ 1.79GHz 480MB of RAM

what it said on my RAM:
CORSAIR VALUE SELECT VS512MB400

My motherboard (i think):
ATIA3/MI53D

Memory type (i think):
DDR-400 (PC-3200C25)

Format (again i think):
184-pin DIMM

just wanted to know what RAM I need to buy?
also does it matter that I only have 2 RAM slots when I buy better RAM do I just take the old ones out and put the new ones in?

P.S: thanks for any help

[caperjack]

you need to buy DDR-400 PC-3200.
yest you can take out he 512 you have now and put in 2 new ones

[OlyComputers]

Since you have a single 512 stick you would probably be best off buying a 1GB and putting it in the second slot. In XP you really wont notice the difference between 1.5 and 2Gb. And +1 to caper, DDR-400 PC-3200.

[jobj17]

OK thats much better thanks for helping:)