Ive tryed Divx, Windows Media Player and Winamp and Divx comes up with a message, and the other two crash. Alll other video files like wmv and mpg seem to play. Thanks for any help.

What was the message? What is your Operating System? Is this a new problem?
Have you been able to play these in the past? Any new software?

Also: look in your Event viewer: rt. click My Computer then click Manage then Event Viewer.
Or: Administrative Tools/Event Viewer or Start/Run/ eventvwr
Open the system as well as the application tabs & look for X errors. Click error line for details.
Post back the source & event id especially of errors that seem to coincide with this issue.

Also view your Error Log via:
[1] Start Menu
[2] Help and Support
[3] Pick a Task
[4] Tools
[5] Advanced System Information
[6] View the Error Log