"Cyclical redundancy"

I keep getting this message when trying to reinstall Civ 4. Am I out $50?

This typically indicates a physical problem with the media such as scratches, dirt, or some type of damage to your DVD or CD. If you can't clean it or somehow repair it then the media did have a 90 day warranty from 2K. Additionally, it's been my experience, that if you present the defective disc at your retailer and request a replacement, most will do so (exact exchange only). If you bought from Direct2Drive, your download may have become corrupt. Do a thorough HDD chkdsk. D2D will have their own support options.
Good luck. Let us know how it goes.

A quick wipe with a dry dish towel did the trick.

Good to hear! Thanks for posting back too