There are a couple of things to try
1 look at this thread
https://www.digitalworldz.co.uk/index.php?threads/253390/
You may get lucky
2 From this link
HP Support document - HP Support Center
What if I forget my password?
If you forget your password, check to be sure that you are entering the password correctly. Please remember that passwords are case-sensitive, so, if the caps lock or num lk keys are turned on while you are typing your password, your password will not work - unless your password only contains capital letters and numbers. Turn off the caps lock and num lk keys, enter your password, and then turn the caps lock and/or num lk keys back on - if you want them on.
If turning the caps lock and num lk keys off to enter your password does not work, follow the steps below to view your password hint.
Press the enter key at the logon screen. The text The user name or password is incorrect displays.
Click OK . The logon screen displays with the password hint directly beneath the Password field.
You should now be able to remember your password. If you still do not remember your password, insert your password reset disk, and then click Reset password . Follow the on-screen instructions in the Password Reset Wizard.
You can now either logon as the administrator (assuming that you have set up an administrator account and you use an individual user account), or you can reformat the hard drive and return the notebook to its original configuration.
NOTE: You should create a Password Reset disc if you tend to forget passwords; you should create a new Password Reset disc if you change your password.
If you forget the power-on password, you have a more difficult problem. Since the power-on password was designed to provide complete security, you will need to contact an HP-authorized service center for assistance. All data on the hard drive will be removed during the service.
WARNING: If you forget the power-on password, the computer must be reset at an HP-certified repair center. Please contact HP to schedule a repair. The Drive Lock password cannot be reset. If you lose or forget the Drive Lock password, the hard drive must be replaced. Please contact HP to order a new hard drive. These services are not covered by the warranty.