Numerous users of Windows Live Messenger are currently experiencing the error code 80048820 when they try to sign in to Messenger. The Windows Live team has published a solution advisory. If you are getting this error as well, the reason might be that you have invalid characters in the first name of your user profile.
Editing your user profile first name
- Go to http://account.live.com/.
- Sign in with the account in question.
- Click the Registered information link.
- Click the Change link next to your name.
- Change the First name to something appropriate with no special characters or the ‘&’ symbol.
- Click Save.
- Attempt to sign in with Messenger again.