For Dell's laptops, power on the unit, then press F12 to bring the boot menu for Recovery and diagnostic.http://www.dell.com/support/contents/us/en/19/article/Product-Support/Self-support-Knowledgebase/software-and-downloads/dell-backup-solutions/Dell-Backup-and-Recovery
Boot Select: Druing the boot up logo, press the key.Dell/Alienware: F12HP/Compaq: F9Asus: ESCAcer: Go to bios MAIN to enable F12Lenovo:
During the boot up, press "F4" key to enter the recovery.F2: enter biosF10: boot select.If you need to boot to
This info provide for nobebook with built-in SSD-Cache which cannot boot normally after installing Windows on it.
How to install Windows