HEELP PLEASE ASAP

Okaay Heey I Need Heelp ASAP .... I Turneed My Laptop Off Once Too Use It The Nexxt Day At Night & I Turned It On Normally In The Morning & Reached The Choose An iD User .... I Have Mine & My Sistuurs User But For Some Reason I Go To Mine & It Says That Its Not Loadinng So I Trieed It Everydaay Since July 5th & It Says The Same Thing All The Time .. But My Sisturs User Works .. Please & I Nevuur Had An Password On It So Pleasee Help Mee ASAP . ThankYou