Windows 10 log in screen keeps reloading itself

[brockyy]

My sisters computer was fine a few days ago but now when she reboots her pc and is in the windows sign in screen it just reloads itself and we cant get a response at all, our mouse cursor moves but keyboard does not seem to respond. I will try to attach a video if i can

 

[brockyy]

https://www.youtube.com/watch?v=R3vHhuDjw5I&feature=youtu.be&ab_channel=bobmucs heres a video of it!