No clue what that means, your going to have to post more information because that could mean anything.
what were you installing?
Can you restart the machine (laptop or desktop)
anything and everything would help.
Hmm, still can't be sure but follow caperjacks advice and only have the minimal hardware to do a clean install. My guess is it might be
1. A scratch on the CD - find another CD or fix scratch
2. Bad RAM - If you have multiple sticks, try just using one. Memtest would be a good tool to use to check the RAM and see if it bad.
3a. Bad hard drive - Find the maker of the hard drive and get their hard drive tester and test it.
3b. Try using a formatting program like "drive scrubber" to wipe the hard drive completely. 1 pass should be enough.
These are just some suggestions as I really still have no clue as to why it's happening. Still need more information to make a better diagnosis.