Re: one more ram question...
It means that your motherboard supports SDR RAM up to PC133, probably, as that is the highest SDR speed (at least that i know of).
Windows XP Pro 17" LCD Monitor (1280 x 1024)
nForce3 250 Chipset Athlon 64 2800+ w/ C'n'Q
1 x 512MB DDR400 CL3 SDRAM 40GB IDE 7,200rpm HDD (8MB Cache)
nVidia GeForce MX420 64MB PCI On-Board Audio