honestly, I am always puzzled how people can break CD's. I mean I am playing computer games since '86 (with 5.25' discs) and never had any issue there...
Here I wrote a 'complete' paper providing some insight into the epidemic of breaksdowns (emotional and diskwise).
The 'sleaveless' disc packaging, its the main culprit quite a bad bid of biznass you will agree.

For monthes I properly protected my
'Start Disc' by placing it back in its specially designated "Civ3 Complete" 3 layered boxset. Then came a time when I needed to reinstall Civ3, oh boy what a mess!
On this day to my horror I discovered The disc going ape sh#t on the install run! Upon inspection its revealed to been scratched in a circular motion like a needle on a record , like a needle on a record
Jerks in packaging had me scratching in a 1 inch area 'record grove' where the plastic disc holder met the back of
'disc 1' in the boxset
SO ya anyone with Civ Complete can see this much easier then I can explain. What will happen is it will lose its install status but alot harder to kill its boot disk function. Let me explain how I found this
After havin bought 'Civ Chronics' and installing it to my old Dell then more receantly, a 3.2 ghz beast of a machine, I was hot with misgiving again when My Civ chronics Civ3
'Disc ONE' was met with a lightning bolt

.
Needless to while stuck waiting for parts on the mega map 'turn time eraser' (latest rig) I thought to ram the scratched disk back in the old Dell drive since reinjected with the 'Chronics' syringe. Well Shabamm! That Thunderous Take 2 intro beat coming off 2 day withdraw was enough to bring me if quadropoligic to my feet. Bonus was an old Anno Domini epic left uncomplete. It was deep sigh of relief for buying the Series twice just for Conquests dosn't come cheap .
(In my town CivComplete gave up shelf space for 'Chronics' when it released )