Windows 10: My sister got a new computer and my computer updated to her settings

So I've had this computer for a couple years and haven't had any problems with it. But then my sister who lives with me and uses my WiFi got a new computer. She has never logged into my computer but when she sether new laptop up, it changed all of my settings. In the settings>account section it shows my first name but all of her information including her email. All my documents appear to still be intact on the computer but it's not my account. How do I fix this and get my account back the way it was? Since she never logged in before, there is only one account on the computer and it should be mine but it all changed. Thanks.

:)

 

New computer for sister

My sister needs a new computer. And we are trying to figure out whats best a desktop or a laptop. her budget is $600 to 800. Put together a build that will last her a long time and be able to run Sims. Thanks

 

New computer for sister

if it only needs to run sims and other things then go for a laptop if you need the portability

 

Computer update

For what? And what will this computer be used for?