So my cousin gave me this model desktop and it was from his job. It was working fine until yesterday when I "wasn't connected to internet". i was always connected to the internet but I decided to wait a day to see if it changes. So today it wasn't working so i decided to unplug the power cord and wait 30 seconds then plugged it back in. Then it told me I had to set it up so I tapped on F2 and then i was told to enter the admin password which me nor my cousin know. 

Basically I want to know how to factory reset the desktop without entering the admin password. Any help? Thank you.