Why does Yahoo Messenger quit, close, and then cause me to have to reboot my modem and pc?

For several weeks now I have been encountering a serious problem when entering chat through Yahoo Messenger. I can log in fine, enter the chat room fine, and send perhaps two lines of text fine, but after less than two minutes Messenger throws me out of the room, shuts down, the chat window closes off my screen, and I no longer have any connectivity to the internet. At this point I am forced to shut down my pc and my cable modem, unplug and replug all the modem cables (after waiting at least 5 minutes), and then boot the system back up. This sequence happens without fail every time I go into chat. I have run every virus scan, adware scan, and spyware scan I own but nothing has helped. My OS is windows xp pro, and I sure would appreciate any help anyone cares to share. Thank you for your assistance.

Why does Yahoo Messenger quit, close, and then cause me to have to reboot my modem and pc?norton antivirus

Sounds like you have a virus or you need to upgrade your microsoft windows (i.e. service pack 2 etc...).

Why does Yahoo Messenger quit, close, and then cause me to have to reboot my modem and pc?security

Two options spring to mind:

A) Uninstall Yahoo! Messenger. Reboot and Reinstall.

B) Reinstall Windows.

If both fail. Contact Customer services.
It sounds like you might have had a virus, Trojan or something that caused damage to your Registry. You should find someone who knows about how to fix Registry problems, because it can be dangerous to try to fool with it if you don't know what you're doing. Back up all your files first.