The computer was infected with viruses, so we had to reinstall the system. After the system was reinstalled, there were two things that made me angry: MSN Messager could not log on, and the system could not be activated.
Failed to log on to SN, error CodeIt's 80048820. Google queries it!
The answer is: this problem is generally caused by incorrect system time. If you still cannot log on to the system, it may be because the DLL file registration information is lost, download this batch file http://www.msn-problems.com/downloads/register-messenger-dll-files.bat and run it, the problem should be resolved.
My system time is automatically synchronized with the internate time server, and the time server is time.windows.com. So I think my system should be okay. I tried none of the methods, I had to trust Microsoft, remove the time server synchronization with Microsoft, and use the Internet time calibration tool to correct the system time.
The system can also be activated, and MSN is also available.