I'd plop a gig into those systems as 512 is anorexic these days. Overall, I'd say yes, go for it as Windows 8 actually runs nicer on xp era machines than xp. No joke. Graphically is better, personalization is better, and performance is fairly clean and will probably breathe a breath of fresh air into those puters. Another consideration would be is if those machines are used often enough to justify the upgrade. My personal suggestion would be to try and partition the hard drives and dual boot the machines with xp and 8 to see if the graphics drivers in Windows 8 will work properly with the older hardware. I've come across an elder HP machine that was built in 2005-6 and its graphics driver works great in Windows 7 as the driver is supported by Windows Updates and displays the proper native screen resolution. In 8, everything works fine except that the driver from 7 doesn't install as it claims it isn't digitally signed or I think wasn't supported. So, it could only display in three non-native screen resolutions. But on another xp machine that was vista ready (theoretically as it only has 512 MB of RAM) everything worked fine and ran fine. Actually I retract my first sentence. If the machines are used for light work scenarios such as Office and interwebsting, and Windows 8 runs fine on them as well, you could probably skimp out the extra RAM as I remember Windows only taking about 200 or so MBs of RAM, and this was with Office apps and other things running as well.