You might have a corrupt file in your Messenger directory. To fix the problem, you need to manually delete the Messenger directory on your C: drive (default), then reinstall the Yahoo! Messenger application.

Please note: Deleting this directory will also delete any archived messages on your computer. If you want to keep them, first move your profile directory out of the Messenger directory:

• Close Yahoo! Messenger (if it's currently running).
• Go to your Desktop and double-click My Computer.
• Select the "C:" drive.
• Go to: C:\Program Files\Yahoo!\Messenger\Profiles

Your folder will be named with your Yahoo! ID. It contains your complete Message Archive. Copy it to another location on your computer before deleting the Messenger directory. You can then move it back after re-installing Messenger.

To delete the Messenger directory:

1. Close the Yahoo! Phone OutYahoo! Messenger application if you currently have it running. Make sure all instances of Internet Explorer are closed.
2. Go to your desktop and double-click My Computer.
3. Click the "C:" drive.
4. Go to:
   C:\Program Files\Yahoo!
5. Highlight the Yahoo! Messenger folder and press the Delete key on your keyboard. (All archives will be deleted if they're not copied. Please see below.)

To install:

1. Close all running applications except for your Internet browser.
2. Visit the Yahoo! Phone OutYahoo! Messenger home page.
3. Click Download Now.