HP pavilion DV4-1430us Notebook

I have a HP pavilion DV4-1430us Notebook With windows 7 (Which before was Windows Vista)This compute was given to me because they did not remember the Administrative Password. I can enter with the Guest Account, but I need Administrative Privilege to install update, anti-virus, drivers and many more things that the computer needs. My question is how can I delete or change the administrative password. Is there a disk that will delete,change, or recovery the administrative password. please help me on this problem.


Thank you,
tonchis