|You need to somehow determine the specs but most of all, you need to know the amount of RAM. Understand that 256MB is the MINIMUM for Ubuntu...it will not run extremely well with that amount. Did you check the link I supplied?|
"With only the minimum amount of memory available, the installation process will take longer than normal, but will complete successfully, and the system will perform adequately once installed. Low-memory systems may be able to use the desktop CD to install by selecting "Install Ubuntu" from the boot menu"
You may wanna consider a lighter weight distro & possibly something a little more Windows-like. Linux Mint is based on Ubuntu...the Mint Xfce Edition has lower memory requirements.
Zenwalk is another Xfce distro:
And there's also an Xfce version of Ubuntu called Xubuntu: