Lenovo IdeaPad Z380 Laptop Computer - 212932U - Gray "grey screen shuts down" Questions

...grey screen for a few minutes until a blinking folder with a question mark in it appears. Often, my computer shuts off after the question mark folder disappears. I have read that booting from a disk ...

screen was grey and a question mark kept popping up.. What is going on? I looked in my manual and none of the procedures listed in there helped at all and now my startup disk is stuck in the drive. it

...down but says it is going to & refreshes screen regularly eg every 15 min. Start your PC and press F8 several times until the boot menu comes up. Then select "Safe Mode with Networking". Now get ...