If you have forgotten your Administrator account password then there is no need to worry as there are several ways to login into the account.
Here are the two ways that you can use successfully:
1. Change the password ( read http://techsalsa.com/break-or-reset-administrator-password-in-xp/ post of mine)
2. Reveal the forgotten password ( read http://techsalsa.com/reveal-or-recover-xp-administrator-password-using-ophcrack/ post of mine)
But some of our viewers wish to know “how to login into the Administrator account through another account”. There is another way of doing this:
Through Safe Mode:
1. Reboot the computer and press F8 at the startup (your key may be different) to enter the Safe Mode with command prompt.
2. We will see the default Administrator account and the important thing about it is that it do not contain any password unless set by us.
3. In the command prompt window, type “net users” command without quotes to see the list of users in the system.
4. To change the password of an account, say ABC, type this command “net user ABC 1234” without quotes and hit enter, here ABC is the account for which we are changing the password and 1234 is the password that we wish to set.
5. If we see the statement “The command completed successfully” that means the password has been changed.
Note: This method will work only if we have not set any password for the default Administrator account at the time of XP installation.