1. Your network status was abnormal at that time, which made it impossible to log in normally;

Method: Please check whether your network has been successfully connected and try to disconnect and reconnect the network. (If this method can't be solved, please try the following method again)

2. When you log in to QQ, there are QQ processes that have not quit;

Methods: Press "Ctrl+Alt+Del", click "Task Manager" and then select "Process". After all the process data of QQ.EXE are completed, log in again. (If this method can't be solved, please try the following method again)

3. The local data of this account is damaged, so it is impossible to log in locally. It is suggested to delete the local data of this number and log in again.

Methods: It is suggested that you find your own QQ number folder under the user on your local computer (if your chat record is very important, please open the number folder and back up "msg2.0.db"; If your custom expression is important, back up "CustomFace.db" and "CustomFace.dbc", you can log in and then overwrite the data you backed up into the newly generated number folder), and then log in to QQ again after deleting it.

If the above methods can't solve your problem, I suggest you completely uninstall QQ software, then log in to download the latest QQ software and install it through another path.

How to uninstall QQ software: Click Start → Control Panel → Delete/Add Programs → Delete in the lower left corner of the computer to delete the QQ software you are currently using.

Note: Before uninstalling QQ software, please back up the chat and other records to avoid losing them.

Tips: If you don't know where Users is, I suggest you click "Start" in the lower left corner of the computer-> "search"->; "all files or folders"->; Enter the user in "All or part of the file name" and search for it.

QQ enthusiasts sincerely answer for you!