問題可能只是日期不對.......看一下日期對不對

Steps to fix the sign-in error 80048820-80048412 for Windows Live Messenger
If you are receiving error 80048820 when trying to sign into Windows Live Messenger you should also get an extended error code.  If this extended error code is 80048412 the problem often occurs because the time and date settings on the computer are incorrect.  The error will appear like below:

 

You cannot sign in to Messenger. Additionally, you may receive the following error message:

We were unable to sign you in to the Messenger at this time. Please try again later.
To let us try and troubleshoot the problem, click the Troubleshoot button.
Error code: 80048820
Extended error code: 80048412

The following steps may help resolved your issue:

To troubleshoot the problem on a Microsoft Windows XP-based computer:
 1. Click Start, click Run, type control timedate.cpl, and then click OK.


 2. In the Date and Time Properties dialog box, confirm that the date and time settings on the computer are correct, and then click OK.



To troubleshoot the problem on a Windows Vista-based computer:
 1. Click Start, type control timedate.cpl in the Start Search box, and then press ENTER.


 2. In the Date and Time Properties dialog box, confirm that the date and time settings on the computer are correct, and then click OK