...is Vista ultimate.plz help? The error message is Yahoo messsenger can't connet.
we are not able to sign you in to Yahoo.
Modem users:
Try again (Please make sure you are online and then try again)

LAN/firewall users:
Setup Proxy(If your know your proxy setting you can configure them her)
Help.

thts the error window which I get.I don have any Antivirus and disabled Windows firewall.tried all the connection preference option.Still it doesn't work ..plz help me..My OS is Vista Ultimate.

When you log onto Messenger, use your e-mail address without the @yahoo.com. If that doesn't work:

Try uninstalling then reinstalling Yahoo Messenger. You won't lose your contacts, I assure you as I've had to do this before due to problems:

To un-install so you can re-install:
Click on: Start
Click on: Control Panel
Click on: Add/Remove programs
Click on: Yahoo Messenger then remove
There are two versions of Yahoo Messenger you can install, the latest is: http://beta.messenger.yahoo.com

The older version:
http://messenger.yahoo.com

The older version is NOT compatible with Vista. I am not sure about the new beta version.