What operating system do you have running on the pxi. If you have a windows OS you will be able to boot it from a usb with Linux on it, ideally kali. Using chntpw you can then reset the password. You can also unlock it if you have locked the account. See this link
https://www.cybrary.it/blog/0p3n/reset-windows-7-via-kali/
sometimes it is a pain to get kali to boot from a usb so just downloading Ubuntu will work but you will need to have an internet connection to download chntpw.
