Memory Upgrade

My motherboard specs state the following:

Memory Type: DDR3
Memory Supported: 1066MHz DDR3, 1333MHz DDR3
Number of Pins: 240-Pin
Number of Slots: 4
Maximum Memory Supported: 32GB - 64bit
Max. Memory Supported Per Slot: 2GB

I currently have 2 2GB cards and need more memory. I'd like to upgrade to the max memory, but I'm confused by the specs. How can the max memory be 32GB if there are only 4 slots and a max of 2GB per slot?

 

Best place to figure what you need, is to go to Crucial.com, and use the tool that you download, which will read your machine's spec's, then pull up a page of the best memory option for your machine.

 

Or further to Brownizs suggestion,
use the Crucial, Corsair, Kingston or Mr Memory websites, and simply enter your computer's details into their memory configurator programs, and that will do the same thing, without you having to download anything. Of course you may not know the details of your computer, in which a computer scanner program such as that from Crucial would be best...

Dumb_Question
2.June.2013
Compaq Presario S5160UK DT261A under XP/SP3
Processor - Celeron 2.7 GHz
Motherboard - MSI MS-6577 v2.1
RAM - 1GB + 512MB (1GB +1GB max) DDR PC2700
PSU - Octigen 300W model 10270PSOTG ('upgraded' from original Bestec 250W PSU [in 2011?])
Nvidia GeForce 6200 graphics card in AGP slot.