Hey guys, I can't seem to boot into xubuntu from a pen drive, even on my first time to explore the os. It hangs everytime at the loading screen.

Info on my system:
Ubuntu 12.04 full install
AMD Mobile 64 processor
1 GB ram (i hope, possibly only 512MB)

It's a really old laptop I use to play around with linux.
Ubuntu works and is installed, but it's too much for my old computer I think. That's why I wanted to try Xubuntu, but it keeps freezing.
I also tried Lubuntu, but it didn't work either although puppy linux did, i just didn't like it.