09-21-2008 06:15 AM
Using your BlackBerry's Browser, go to:
Scroll to the bottom of the page and click the [Search] button. Your device will be scanned, and all IM clients available to you based on your Device model and OS, as well as your Carrier.
Then just click the Download Windows Live Messenger link to download and install it!
This is your best option as some carriers do not support all the IM clients available. For example, AT&T will not send the service books needed for AIM or ICQ!!!
You can also get to the link above by clicking the Instant Messaging for your BlackBerry Smartphone link at the BlackBerry Mobile home page at http://mobile.blackberry.com.