My computer screen randomly goes black?

How to put a computer on lock when screen goes black?

• ok so i recently bought a compaq computer and it has windows vista. ok so you know when you dont go on the computer 4 like 5 minutes the computer screen goes black and then you have to wiggle the mouse to make the screen come back. i want to know how do i set it like so when i wiggle the mouse it goes to the screen were you have to type your password to get into the computer. please give me step by step instructions on how to set it as this.

• Answer:

  windows key + L if you wish to lock the computer right away otherwise, on desktop -> right click ->personalize ->screen saver check the "on resume display log on screen" option. click ok