@ Joseph561 This a somewhat old PC. According to various sites, you should be looking for PC133 SDRAM Memory The maximum amount the motherboard/BIOS will accept is 512mb. U don't say how much the PC currently has. Good luck.
Ok well if your max is 512 then you are at your max and dont need to buy anymore ram. Honestly unless you just like reviving the old computers like me, then yours is not gonna work for what you want it to do. Yours is most likely reporting it as 511 because your onboard video is set to 1mb in your bios, thus taking 1mb from the 512, which leaves you with 511mb.