For no reason, I was unable to connect to MSN Messenger today.
I got the error message as below.

Fix this error / possible solution
To correct the time on your computer, double-click the clock in the bottom right of your screen, in the window that appears you should check both the time and date.
If you use Windows XP, you can automatically correct the time by clicking the “Internet Time” tab, next click the “Update Now” button.
I checked the date of my Windows and found out it was back dated to year 2004. Once I set it back to 2005, I was able to connect back to MSN Messenger. Yea! 😀
Credits to MSN-Problems for this content.
Update 19 December 2005: A new full install MSN Messenger v7.5.0322 is out. Please download from this link. It should fix the MSN Messenger Error 80048820.