Ubuntu Installation :: Upgrade - 8.04 To 8.10 On Older PC?

I took the splash about 3 months ago when I picked up a cheap book on Ubuntu that came with the 6.0 release. I had an old clone PC that I built back around 2000-2002. My apologies, but I can't quite remember the hardware specs exactly. But anyway version 6.0 worked pretty good, and I soon after upgraded via the Synaptic manager to 8.04. Everything ran a bit better on this release.

I was working on upgrading to 9.10 eventually, so I went from 8.04 to 8.10 first. However, when I rebooted after the install the GUI failed to launch. I got a lot of text on the screen saying certain things were being checked and there was an [OK] next to all of them save one. Nvidia, my graphics card had a [FAIL] next to it. I'm inclined to think this is the problem. I'm guessing the hardware is a bit outdated for the version of Ubuntu I am using?

I tried a couple of reboots and got the same messages. Eventually found my way into the Recovery mode where all the options were recovering 8.10 - not my previous version. So my question is how do I roll back to 8.06, or is there a way to update the hardware drivers so it will run on 8.10 without buying new hardware? I did somehow manage to get to a Prompt where it was asking for my Linux Login and Password.. it let me login and now I have a "DOS" prompt... not sure about the terminology if you still call that DOS or not. I'm a noob and still trying to learn the new lingo.

I don't have much to lose.. some pictures, but I figured out how to navigate to those at the prompt so I'm going to save those to disk. If I have to wipe the drive and start over I don't care, but I thought I would throw out a post here and see if anyone had a recommendation.