I cannot sign in yahoo messenger. it keeps on saying encounter a connection problem.almost 2 days still i havethis problem to sign in.thanks.

You can use web messenger, like KarooLark web yahoo messenger http://karoolark.com/#yahoo

Click the "Messenger" menu in Yahoo! Messenger and select "Connection Preferences."
2. Enable the "No network detection" option and then click the "OK" button at the bottom of the window.
3. Yahoo! Messenger will ask you if you want to sign in again with your new proxy settings. Click the "OK" button.
4. Enter your Yahoo! ID and password and click the "Sign In" button.

you may have a registry problem download registry cleaner reginout to fix the issue

If you want to sign in, better check your user id and password for capital letters.
Check also if your email account is accessible. If its not then you won't be able to sign in to you yahoo messenger...
Check also if your internet connection is stable. Disabling the Firewall is also recommended.
Upgrade your Internet Explorer to its latest version. This is where yahoo messenger rely its connectivity.

Hope it helps.

Just post back if you still have questions

I have 3 suggestions: 1. Go to Messenger>Connection Preferences> then, you choose either connection directly to the internet or connect via a proxy server, and then choose type of internet connection>OK>Sign in again... let's try this, may be you can solve this problem. OR 2. Check your internet connection, may be your connection encountered problems...or i think better you should check your firewall settings. I think you should check your firewall settings. If you use Personal Firewall, make sure it allows your connection to receiving incoming connections and allows you to sign in your yahoo messenger, check it out, may be it blocked your yahoo messenger from sign in. OR 3. Open your Internet Explorer>Go to File>Then, 'uncheck Work Offline', make sure your Internet connection is not working offline. Then, close Internet Explorer, try to sign in your yahoo messenger again. I hope these can be helpful! Try these! Good Luck! Hope it was helpful!

It may have 2 problems and 2 solutions:-

Firstly, this error occurs when your connection preferences are notproperly set. I'm not talking about your Yahoo! ID and Password here,but you may need to adjust certain features depending on what networkyou're on. Let's says for example, if a firewall protects your network,it may block yahoo messenger when it tries to connect to the server.You need to change your connection settings, click the Messenger menuin yahoo messenger and select Connection Preferences. Select FirewallWith No Proxies. Select your Internet Connection type from thepull-down menu at the bottom and enter your Home Country if theseoptions aren’t grayed out. Click OK and login again using the newsettings.If this option doesn’t work, click Connection Preferences inYahoo! Messenger again and select No Network Detection. Try to loginagain using the new settings. In some instances, you may need toprovide yahoo messenger with the IP address of your firewall or proxyserver (you can get this information from your network administrator orfrom your Internet service provider). Click Messenger and selectConnection Preferences again. Select Use Proxies. Enable either theHTTP Proxy or the SOCKS Proxy as needed and provide the proper address.Click OK and login again using the new settings.

Secondly, if you are using IM9 there are sign in problems. This is whatyahoo has to say.Try an updated version of Yahoo! Messenger 9.0(9.0.0.2128). This latest build includes a fix for the sign-in issuesthat have been affecting some users. If you were seeing an error code“81003005” when trying to sign in, this latest version may fix thatproblem. Even if you were experiencing a different kind of sign-inissue, I recommend installing this latest version.

Hope it can be helpful!
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Try selecting the 'Messenger' dropdown at the top of the window and selecting 'Connfection Preferences' and then select 'Connect via a Proxy Server'. Choose 'HTTP proxy' and then click ok. Try to log in again.

internet explorer might be offline... open iternet explorer and connect it to the internet... it worked for me

i cannot sign in to yahoo messenger. it keeps on saying "messenger encountered a connection problem. please check the network connection and then click "try again". (81003004

click the "messenger" menu and select "connection preferences" Select "Firewall with no proxies" click "Apply" you should see a message asking you to sign in again click "oK"
info found in yahoo help here is the link
http://help.yahoo.com/l/us/yahoo/messenger/messenger9/messenger/mstanoconnect.html

Try the following:
click preferences > click connect directly to the internet (again..even though it probably is checked) > choose your connection and connect

Have had the same issue in the last few days and that is what resolved it for me.