i have a dell dimension 8400 desktop pc and have been having issues with it since shortly after buying it new (many years ago).
it randomly freezes up, crashes and restarts all the time.
this is what i have done so far to try and fix it.
i have no idea what is likely to cause the issues i am having.
what should i do in order to repair it?
Some hard drives are warranty for 90 days or less.
How does it faire with a Knoppix Boot DVD?
Although typically used as a Live system, you can also install Knoppix on a hard drive. Machines supporting boot-up from USB devices can load Knoppix Live from a USB stick. Knoppix version 6.7  uses the 188.8.131.52 kernel and defaults into the Lightweight X11 Desktop Environment (LXDE). This version includes Chromium 12, LibreOffice 3.3.3, and a new version of the ADRIANE (Audio Desktop Reference Implementation And Networking Environment) desktop for blind and partially sighted users.
A dimension 8400 is very old. Knoppix is one of the versions of Linux that runs on most hardware and can be run in
LIVE mode aka you install into ram as you boot.
Knoppix is a Free and Open Source Live Linux CD based on Debian GNU/Linux. Live Linux CD means that the computer boots and runs completely from cd. Nothing is installed on your hard drive in order for you to experience many of the Open Source software packages available. Knoppix includes recent Linux software and desktop environments, including such applications as OpenOffice.org, Abiword, Gimp, Konqueror, Firefox, Apache, PHP, MySQL and hundreds of other quality open source programs. (See "complete list of packages included with Knoppix" for more information.) Knoppix.net allows you to look at the FAQ's and Documentation, participate in discussions on the forums, or just burn a copy of it and try it out! - You can download it ( CD or DVD size ISO files ) or buy it from a CD distributor, more info on the download / buy page.
The documentation found here is organized in several sections. The goal is to take you from the very beginning as you learn how to use Knoppix all the way to advanced applications of the Live Linux CD.