I totally agree with Impavidus.
I am running Lubuntu on an old Compaq Windows ME machine .. 512MB RAM max. If your computer is RAM expandable to 2GB ... I HIGHLY recommend more than 512MB. That is only enough to slowly chug along ... give yourself at least 1GB ... and Lubuntu should zoom along well. Not so with 512MB. Memory is cheap ... you will not like ANY distro with only 512MB .... it barely performs without more.
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