Police have released this CCTV footage of Hannah walking along a footpath at Bidston Hill on her way to meet her killer, Adam Lewis.
Detective Inspector Mark Tivendale, of Birkenhead CID, said: "Hannah was in the prime of her life and she should have been looking forward to the rest of her life but sadly her future was taken from her by Adam Lewis.
"The sentence today will not bring Hannah back but hopefully the conclusion of this case will bring some closure for Hannah's family and friends."
Lewis, 18, was sentenced to life imprisonment at Liverpool Crown Court for the murder of Hannah, 17.
Hannah was tied to a tree, sexually assaulted, strangled and attacked with a knife by Lewis, of Fairmead Road, Moreton, Wirral, in May this year.
The partially-clothed body of the youngster, who was living in a hostel for homeless young people at the time of her death, was found hidden under leaves and dirt in woodland at Bidston Hill, Wirral.
Lewis had denied murdering his girlfriend but changed his plea to guilty on Monday, shortly before his trial was due to begin. He also admitted two counts of sexual assault against his victim, two counts of burglary and one count of arson.
Passing sentence, Mr Justice Holroyde told him: "Only you know what you did to Hannah and in what order you did it. It is, however, clear that you deliberately inflicted cruel injuries upon her which must have caused her immense pain and suffering."
He added: "Adam Lewis, that was a prolonged, merciless and terrible attack, which must have been agonisingly painful for Hannah Windsor before she died. You must have known what dreadful pain you were causing her."
The judge said Lewis showed "dreadful cruelty", and added: "I am quite sure that your murder of Hannah Windsor involved both a sexual and sadistic element."
Members of Hannah's family sobbed as they followed proceedings from the public gallery. Speaking outside court, Hannah's mother, Gaynor Murray, broke down in tears as she said: "He deserved what he got and I'm so made up. Today was the best thing that could have happened - now we can actually mourn in peace for Hannah, my beautiful little girl."