Upgrade help!!!

Hi, i just finished "upgrading" my little bros' pc.

He had an Asus p4pe800 motherboard with a 2.00Ghz Pentium4.

64mb graphics card and 256 Ram.......i know it's cr@p.....LOL

I changed the ram and put 1gb ddr and bought a Radeon 9600.....

I formatted the pc installing win2000 (since it was the only one lying around).

Now that the pc is up and running it's gotten so damn SLOW!!!!! and i mean slow....like slow as hell...

how can this be....more ram (more than double)....more graphics memory (waaaay more than double) and the machine looks like it's choking on an asmatic attack!!!!!! what's wrong??????

i didn't think about that......thnx

If i set it to ddr266.....isn't it best on auto?