Password Authentication System Prompt

Hi,

I am writing on behalf of a school that we provide support to. They have a bank of Dell Latitude E5400 laptops, however on one of the PCs, when turning it on, a message saying

This Computer System, #SERVICETAG, Is Protected By A Password Authentication System. You Can Not Access The Data On This Computer Without The Correct Password. Please Type In The System Or Administrative Password And Press Enter.

I have the service tag and proof of purchase etc - can this be resolved?

Thank you

Tom.