Have you met? The 10 most prone to PC disasters (9)

        Question 9: Forgot your login password, you can't enter the Windows system.
Possible reasons: Go check with your family health doctor and do a comprehensive diagnosis.
Workaround: As the Windows version changes, fixing passwords becomes more tricky, thanks to Microsoft's ruthless security improvements. However, there is no need to give up hope.
If you have forgotten the Windows XP system login password, try logging in to another user account with administrator privileges (after purchasing a computer, there will usually be another account such as "Owner"). Any administrator account can reset the password for any other account. If you are not using the Windows XP style login screen (an icon is displayed before each user), you can try to log in as the “Administrator” account, which is hidden on the XP-style login screen. If you are using the XP-style login screen, press the -- button to return to the old Windows NT system login screen. You can enter the account name such as "Administrator" to log in.
1. If there are no other accounts on the computer, you will need to ask for a third-party tool to reset or crack the password. Ophcrack was the first such program I wanted to recommend to you. Download this free software from ophcrack.sourceforge.Net on another computer and burn it to a disc. Use this CD to launch the computer that forgot your login password, then take a look at Ophcrack's skills. Use a huge password library that resolves passwords for all accounts on your computer in minutes.
2, you can also try another tool to reset the password, if other methods do not work. But keep in mind that the risk of using this program is that the data on the hard disk may be lost, or worse, the system will crash. Offline NT PassWord & Registry Editor and Emergency Boot CD are both free programs, there are also boot CD versions, and if you are not so familiar with the command line, they are easy to use. They all unlock the Windows login password for you and are available for different versions of Windows.
3, if you forget the BIOS password, you can try to reset or bypass them. First, try to see if the passwords listed in the Tech FAQ are correct. If it's not correct, reset CMOS - follow the solution in "Problem: Computer can't boot". Restore BiOS to its original state. Replace the CMOS battery and set the jumper to its original position, then restart the computer.
Avoid recurrence: If you often forget your password, consider writing it down and putting it in your wallet, or in a bank safe, or in your home safe - just make sure you don't lose your key.