1. Make sure that you are connected to the Internet. Start Microsoft Internet Explorer, and then try to visit the following Web sites:
Messenger service status
Microsoft web site
If you cannot visit these sites, contact your Internet service provider (ISP) for information about how to set up your Internet connection so that you can visit both secure (https) and non-secure (http) sites.
2. If you are able to visit the Messenger service status page and notice that there is a service issue, please visit the site later to determine when the service is available so that you can sign into Messenger. If the site indicates that the all systems are stable and running, go to the next step.
3. Clear the proxy settings in Windows Live Messenger.
3.a. Start Windows Live Messenger.
3.b. On the Tools menu, click Options.
3.c. Click Connection in the left navigation pane.
3.d. Click Advanced Settings in the Connection Settings section.
3.e. Delete the content of the SOCKS field.
3.f. Click OK two times to save the settings.
3.g. After you clear the proxy settings, verify if you are able to sign into Messenger. If you are still not able to sign into Messenger then please go to the next step.
4. If you are using Windows Vista, disable the Auto Tuning Networking feature:
4.a. Click Start, click All Programs, click Accessories, and then right-click Command Prompt and choose Run as administrator.
4.b. Click Continue when Windows requests permission to continue.
4.c. At the command prompt, type the following command, and then press ENTER: netsh interface tcp set global autotuninglevel=disabled
Note: This command disables the Window Auto Tuning feature.
4.d. After you disable the Auto Tuning Networking feature, verify if you are able to sign into Messenger.
5. If you are still not able to sign into Windows Live Messenger then please re-enable this feature using the information below and then go to the next step.
Re-enable the Auto Tuning Networking feature by typing the following command at the command prompt, and then pressing ENTER:
netsh interface tcp set global autotuninglevel=normal
Note: This command enables Window Auto Tuning again so that you can take advantage of the network throughput performance increase it provides.
6. If you are using Windows Vista and you also use a router (eg. Linksys, D-Link, Netgear) on your home network to connect to the internet please visit the router manufacturer’s website to update to the latest firmware for that product.
(
from windows live support)
Good Luck
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