My WMP library plays the same song regardless of what song is selected in the library, at least for the 10 songs I checked. This appears to be a corrupted library index so I decided to try erasing the index thus forcing WMP to recreate the index from scratch. Unfortunately I can't find the index. I would like someone to validate my proposed solution, or propose a better one, and tell me where to find the index. Thanks for any help.
Solution: How fix a corrupted Windows Media Player Library?