How to set up password in my PC so no one get access to it.

If you currently don't need to enter a password, your user account may have a blank password or autologon enabled. Try changing your password first. The exact steps vary depending on what operating system your are using. See Change Password - How Do I Change My Password in Windows?

If you want to make it so no one can even boot your computer many systems have a password at the BIOS level. Press F8 or F10 or DEL when first turning on the computer (it usually tells you onscreen what key to hit to enter the BIOS setup) and hunt around in there for where to add a BIOS password.


Warning, this is a much deeper password lock that a password on a Windows User account. If you forget your password, your computer will become a very pretty paperweight.