how to reset bios on pro book 4520s

[hillaman21]

my laptop freezes on the welcome to windows screen so I tried to reset the machine but I bought it second hand and it requires a bios password which I don't know ! how can I reset the administrator bios password !
I already tried to remove the CMOS battery but it didn't work

[mahemac]

Dear Customer,

Welcome to HP Support Forum and we are glad to assist you.

This is to inform you that all HP Business Notebooks such as Probooks or Elitebooks have more stringent security than consumer models infact they don't produce 'halt codes', the password cannot be derived from the Serial Number and the code is stored in non-volatile memory so removing the RTC cell will not reset the password in this case.

Please have a look at this link. 

http://forums.mydigitallife.info/threads/49497-HP-​​Probook-Elitebook-BIOS-Password-Reset-Utility

Please Contact HP Business Notebook support they should be able to send you a customized SMC.bin file which you can use at boot to reset the password.

Hope this helps, for any further queries reply to the post and feel free to join us again

[REO51ST]

@hillaman21

Contact HP.

 http://welcome.hp.com/country/w1/en/contact_us.html

Or download these files.

 https://www.dropbox.com/sh/zu4kdgxm052l87d/AAAMi-kfX4AVH8oTCbsOM4X9a?dl=0

Insert clean USB flash drive.

Then run USB Image tool.

Choose the flash drive then click on RESTORE.

After restore remove flash drive.

Insert flash drive into locked laptop and boot.”If HDD is installed remove before booting.”

At C:\OUTPUT   type CD..   “Then hit enter”

Type HPBR    “Then hit enter”

First thing is to save your settings.

Select #3 re-program.

Press “S” to save system information.

Type HPBR and hit enter.

Since your model is not listed select “SHOTGUN.”

After reboot repeat same as above.

Some instructions here.

http://mazzifsoftware.blogspot.com/2014/01/hp-bios​​-unlock-for-dos.html

More help here.

http://forums.mydigitallife.info/threads/49497-HP-Probook-Elitebook-BIOS-Password-Reset-Utility?s=ad...

Let me know the result so I can update my list.

REO

I must inform you that these services are not endorsed by HP, and that HP is not responsible for any damage that may arise to your system by using these services. Please be aware that you do this at your own risk.