I second bonixavier, Slackware runs very well on older hardware and is easy to install, it doesn't have a guibased installer and you'll always know what's going on while installation.
Take a look at Slax http://www.slax.org/
, a Slackware-based small distribution. It runs well on old computers. Boot Slax and check your system, if Slax doesn't boot be sure that you have a hardware-issue.
Slax is not installable.
If you've booted Slax, please post the output of
I'd recommend to check the system with Slax before installing another distribution.