I would recommend the version of Puppy Linux based on Ubuntu 12.04:
My only issue with puppy is that it is pretty sparse. Yeah, it has an extremely small footprint but I think most folks would be happier with, say, lubuntu...especially if you're a neophyte transitioning from winxp.
Don't hesitate to nuke your current linux install. First, Xandros is awful and should never have been installed in the first place. Almost any modern distro properly sized will work much better. As you're learning about Linux it's good to be experimental.
I haven't hung out here in a long time but this forum used to be a go-to spot for eeepc users. It's not as active as it used to be but some searching might help you learn:
Get rid of the Xandros. I gave up on it when I found it wasn't updating firefox automatically and I was being warned my version was obsolete.
I have Puppy installed on a 2GB SD card for occasional use and it works well.
Pentium 4, 2.4 GHz 1.5GB RAM
Computers are my mid-life crisis - it could have been worse!
I have installed the puppy Linux and found it to be great fun just messing around for a couple of hours - so ,much more navigable than the xandros version I have permanently installed on my machine. I want to completely replace the xandros version I have on the maqchine with the puppy version I have on my USB so that when I log off and remove the usb then log back on again it will load the puppy and not the xandros as it is doing now. Do I have to be online to do this or can I do it from the machine as it is?
Thanks friends, I am getting there but I am making myself a little dizzy with the speed I am moving at ha...