Inspiron 15 3510 Bios update failed

Bios would not update through Dell Support Assist.

Downloaded Bios update file Inspiron_3510_1.14.0.exe  as instructed by Dell support. At start of execution it requested Admin password.  I assumed it was asking for the default system administrator password set on the computer. I entered the password that I have set for this but it does not accept it.

Any idea what it is looking for.