Restore

Most laptops and computers come with a recovery partition that can be used to put the laptop or pc back to how it was when you opened the box. Before attempting this, you should save any documents, pictures, etc. to another hard drive or USB thumb drive because it will erase all of your files and programs.

Some will give you the option to restore your laptop/pc to factory-state withing a program in Windows, such as HP Recovery. More often though, it is through an F11 key or F10 or some other F key as the laptop/computer is booting up.