dell inspiron 9300

hello there,i purchased a dell inspiron 9300 from ebay and seller had no charger so he couldn’t test,but when i started it,it displayed an admin password ,i contacted seller but he bought it himself from a company closeout with bunch of other electronics and couldn’t help me, i tried everything but couldn’t pass that password,i would appreciate any help before i take to a shop and get chared,thanks.