Disc is unreadable - Microsoft Xbox Console

Just one disc? Try another disc to make sure it isnt the xbox.

If its just the one disc, you can try having the disc re-surfaced and try again, or you will need to replace the disc.

If its multiple discs not being read, then the laser needs to get cleaned. So try a drive cleaner. If not, Microsoft may need to fix it up for you.

While I do agree with nealj121, the original xbox has been known for it's optical drive failures. If cleaning the laser (with one cuetip coated with rubbing alcohol, and another dry) does not help, then you do need to replace your drive. You can find replacement Xbox drives for cheap all over the internet at places like ebay. I've listed a simple instruction on how to replace here: http://www.fixya.com/support/t4324901-old_xbox_says_not_recognize .