Windows – Run Yahoo Messenger in multiple instances

You can have Firefox check right now if it is the default browser:

Tools > Options > Advanced > System Defaults

Then click Check Now.

You will see a prompt which will tell you if it is or isn't. If it isn't, simply click Yes and it will set itself as the go to browser for your computer.

On top of that, you may also need to check the following box:

☑ Always check to see if Firefox is the default browser on startup

When you re-installed YIM, it might have reset your default browser to Internet Explorer.

If that still doesn't work, Firefox might be only thinking that it's set as the default. In which case, go to the Control panel for Programs:

Start > Control Panel > Add or Remove Programs > Set Program Access and Defaults

Then open up the Custom configuration and set Mozilla Firefox as your default browser.

Click OK and YIM should now open up any links in the default browser, which has been set in this case as Firefox.

Your question seems to have been thoroughly answered here:

Internet Explorer is used to sign into Yahoo Messenger. If you have another browser set as default, IE will still sit as a link between your browser and Yahoo Messenger. For this reason most troubleshooting is concentrated on Internet Explorer.

1. Upgrade IE and update any support software (Flashplayer, Java, Shockwaveplayer)

2. On the sign in page, click 'Messenger' > Connection Preference. Toggle between 'Connect direct to the internet' and 'Proxy setting' to make sure the information is correct in the lower 2 boxes.

   Check these settings in IE (even if you have another browser set as default):

   • Tools > Internet options > Connections > Lan settings > check 'Automatically detect settings - uncheck other options.
   • Tools > work offline - make sure this is NOT checked and has a red X through it

    

3. Disable your firewall and test to see if you can sign in.

4. Control Panel > Internet Options > Connections > LAN Settings > Uncheck Proxy server, check automatically detect settings.

5. Control Panel > Internet Options > Connections > dial-up and virtual private Network setting > select your default connection > setting > check automatically detect setting

6. If you are unable to sign into this secure page: https://login.yahoo.com/config/login?.src=fptx._intl=uk. Copy the yahoo https address above and paste it in:

   IE > tools > internet options > LAN settings - check automatically detect settings > Advanced - paste in 'Secure' window > OK