Sounds like you have a virus or malware on the laptop. The only fix is to remove it.
Try starting up in "Safe Mode" and see if it will load fully. If it does, then you can try fixing the issue. NOTE: In "Safe Mode" you have limited access. Now if it won't even load up in "Safe Mode" it may require a full system restore, but I would consider taking it to someone before doing that, as you would lose everything.
How to enter "Safe Mode" when booting the computer.
In Windows 8 and 10...
As your computer restarts, press F8 (possibly a few times) to enter "Safe Mode"
a. Press the "F4" key to Enable "Safe Mode".
(The computer will then start in "Safe Mode" with a minimal set of drivers and services.)
b. Press the "F5" key to Enable "Safe...