If you don't like anything that other users use your computer when you're not there, and you want, first and foremost, to preserve your security and privacy, then what you need is a program like PC Locker Pro.
The mission of PC Locker Pro is to completely lock the computer with a simple combination of keys that will display a lock message on the screen, also disabling the mouse. Logically, if you enter the unlock password (which only you will know), you can normally use the computer again.
If someone tries to access and puts a wrong password in PC Locker Pro, then the computer will shut down.
You can free download PC Locker Pro and safe install the latest trial or new full version for Windows 10 (x32, 64 bit, 86) from the official site.
Devices: Desktop PC, Laptop (ASUS, HP, DELL, Acer, Lenovo, MSI), Ultrabook
OS: Professional, Enterprise, Education, Home Edition, versions: 1507, 1511, 1607, 1703, 1709, 1803, 1809