OS for low ram computers

choose my operating system, i have a pentium 4 1400MHz, 128 Mb of ram, NVIDIA GeForce2 MX. right now im using Windows 2000, and i was wondering what i could use for a OS that works well on low Ram machines?

Whatever you choose, can you go pick up some more RAM? You'll be happier in the end. It doesn't cost much and it'll make such a difference.