PC3200 RAM in a PC2100 slot?

Hi,
I'll try to be as clear as possible in this posting:
Last fall I bought several computers in their components, assembled them and set up a workarea. At the time of purchase i didn't really feel like digging out the manual so when it came to the memory, i told the guy to just give me 256 megs of what was compatible with the board. The machines all work fine, although i find they can be a little slow. Especially when compaired to computers with identical specs, but of a different purchase. I decided i'm gunna upgrade to 512 megs ... pop open the case to check what they gave me, saw a DIMM of PC3200 at 400Mhz. no problem, order online, have a coffee and go home. Just for fun i pull up the manual on the Asus website and see that the boards were written to be PC2100 compatible at 333/266mhz! Crap, and i just bought all this ram... Will the 3200 ram just downgrade itself to run at 266 or 333? Or has there been hardware conflicts all this time and THAT's why they seem sluggish? If everything's cool,what can i do with bios settings as far as making the board take as much advantage of the 400mhz potential as i can? Keep in mind, it only knows how to speak pc2100 and i'm giving it pc3200...

Thanks for all and any advice... and i know.. next time look up the specs first..

Pat

it will work just fine. The memory will rum at pc 2100 no prob! It just gives you rum to overclock!! I have pc 4000 in my computer, but im running it at pc3200 and works great!

all that will happen is you pc 3200 will run at pc 2100!