If u don’t want to install full time, u can try knoppix 5.0 CD or any older version. Just for the info, I had a Celeron 1.8 GHz with 384 mb RAM and use to run knoppix 5.0. the system was slow but just ok for surfing.
Even now, i use knoppix 6.2 DVD on athlon 240 with 2 gb RAM. Things work fine for me.