Seems to install and will NOT start up! I've tried running it in various compatibility modes but no luck. Nothing at the Microsoft sites I can find about this. Everything WAS working until 3 days ago and then just stopped. I rebooted and it started and ran for a few hours and then stopped again. I can't reboot every time I want to use Yahoo Messenger. Any suggestions or tested fixed would be appreciated.

Uninstalled, rebooted, still not working. I'm running Trillian at the moment which seems to work fine however I'd prefer to just run Yahoo Messenger.