I downloaded messenger 9.0 and since then my messenger isn't working. Any suggestions?

goto add/remove and un install it, then re install it

You may have too many programs running in the background draining your system's resources which is causing the problem.

Tuneup Utilities 2007 is an excellent program which has a Start-up Manager Tool which you can use to disable unnecessary programs from automatically starting up when you boot or restart your computer: http://www.download.com/3000-2094_4-10698444.html

Please try un-installing then re-installing your Yahoo Messenger:

To un-install:

Click on: Start

Click on: Control Panel

Click on: Add/Remove Programs

Click on: Yahoo Messenger then remove

Re-install Yahoo Messenger by clicking on one of the following links:

For Mac:

http://messenger.yahoo.com/mac.php

For Windows (Including Vista):

http://messenger.yahoo.com/download.php

The new version of Yahoo Messenger just released (9.0 Beta):

http://beta.messenger.yahoo.com/

(Now run Tuneup's Clean-up Utility.)

Everyday there are questions about messenger 9. 0. Its a beta , beta means unfinished. Uninstall it and go to one of these sites and download a previous version for the time being. oldversion.com filehippo.com or freecreed.com ay these sites you will find every yahoo messenger that ever existed. When they go the 9. 0 bugs sorted you can download it and use it again . Good luck I hope you get sorted.