[ubuntu] Cannot boot from a liveCD or a Flash Drive

My system was automatically upgraded after a 6 month absence and I had difficulty with my graphics driver but the problem was solved. After that, I needed to move a directory (I have already moved the Home directory, so I was going to move /usr next.) To do that, I thought I would need a live installation disk so that I could work this out. It turns out that I am unable to use a liveCD or flash drive with Ubuntu on it. I have checked my memory and that doesn't seem to be the problem. Every time I try to boot I get a kernel panic error.... Kernel panic - not syncing - Fatal exception in interrupt. The screen just remains inactive with the cursor blinking. The only way to recover is to power down. I have tried several times and it always does the same thing. I certainly could use some advice.

I'm not sure how to trouble shoot this error. I could try a reinstall but I'm afraid I'll just get the same message and I won't have any system at all.

Thanks in advance for giving this matter some thought.