Linux vs XP - Which's better for Educational Games?

Me and the wife have been butting heads lately about who's right. See, I got this old Pentium III machine collecting dust and I revived it so my son can use it to play educational games and watch videos.

Well, the point of contention is what OS to use. Being the house geek, I decied to go Ubuntu, it's naturally safe and more reliable. I installed Edubuntu, a derivative of Ubuntu that's geared towards youn learners. Well, it turns out the wife had other ideas. Mainly she wanted Windows on there so the son could use it to play educational games and read stories on KOL. And there are a whole lot more 'commercial' educational software on the Windows platform. I them 'commercial' but they're actually popular titles. Stuff most non-geeks are familiar with. Take for example the series Baby Einstein, Jump Start or Reader Rabbit.

My decision stemmed from the face that the machine will definitely run slower on XP since it only has 384 MB of RAM. Another is the safety aspect, though I could use something like OpenDNS to filter out unwanted sites. When it comes to reliability and being kid-proof, there are software solutions out there that allow you you basically 'freeze' an XP configuration so that everytime the machine reboots, it goes back to the default. No changes will be written. Bad news for security updates, though who's updating XP now? Support for XP had ended months ago, so after updating to the last updates, you can 'freeze' it and restore everything at every boot. 

Bottomline, XP is doable as a kid-proof solution with additional help from other software. Edubuntu is better in terms of managing the desktop. The option is there too for using it as a LiveCD, making it kid-proof from any damage that can be caused by indiscriminate clicking.

So who has a better idea? I haven't decided yet.