lozano, the attached link will give options for you to try and how to perform an HP system recovery to completely erase all files, including password information, and go back to the way the system was when it was purchased. There is password recovery software available out there, to be used at you discretion, some computer repair shops may even offer this service for small fee or free.
Check the attached links,instructions and guides for more info. and things you can try to get up and running, Good luck.
I hope this helped you out, if so let me know by pressing the helpful button
http://support.hp.com/us-en/document/c01728332
http://www.wikihow.com/Reset-a-Windows-XP-or-Vista-Password