1, computer crash: If the computer has crashed, the keyboard and other devices can't be used at all. At this point, you can restart the computer, and if the fault still exists, you need to reinstall the system.

2. The keyboard is not turned on: If you use the numeric keys in the keyboard to enter the password, but numlock is not turned on (the indicator light of numlock is off), you need to press the numlock key first, and then enter the numeric password.

3. Keyboard failure: The above operation is invalid, and the keyboard failure is not ruled out. You can replace the keyboard interface or directly replace the keyboard.

Password is a symbol compiled according to a specific law, which is used to transmit the information of both parties. Password is a confusing technology, and users want to turn normal (identifiable) information into unrecognizable information. But this unrecognizable information part can be reprocessed and recovered. Password is a general term for "password" in Chinese. In fact, the "password" entered when logging in to websites, e-mails and withdrawing money from banks should be strictly called "password" because it is not the original "encryption code", but it can also be called a secret number. A symbolic system (such as a message) that is mainly limited to personal understanding. Such as cipher telegrams and cipher typewriters.