I dual-boot Win 98SE & Puppy Linux (4.3.1) on a HP Vectra VL Series 7, 266mhz Pentium 2, 192mb PC100 RAM. (IIRC This system's around 12 years old.) I'm very pleased with the performance.
And for really old systems, there's always Damn Small Linux, which reportedly will run on a 486 w. 8mb RAM. It's only about a 50mb download.
I use Linux Mint on a HP VL400DT, Pentium 3 w. 512mb PC133 RAM. (No install, I just use the live CD.)
And Knoppix might be worth a look.
Good advice, and thank you to all. This box is a 1.6G P4 with 1G of RAM. I may need new BIOS but I’m gonna try and use it. If all that fails, new box time. What the hell, that is only a few hundred bux.
The new version of Puppy Linux is now based off Ubuntu for hardware compatibility... particularly with wireless cards plus you can access the universe of Ubuntu repositories for all the free software you’ll ever need and then some.