On pressing power button , dell logo appears and after that it's showing "no boot device found press any key to reboot again".On rebooting again it's showing similar error.
If after sometime I am able to login then suddenly blue screen appears saying your pc ran into problems and again on booting similar error of no boot device found comes up.
If am able to login in my dell inspiron 7520 turbo laptop then it's taking more time for the desktop to appear .
Sounds like a hard drive headed for the recycle bin. F12 at powerup - run an extended hard drive diagnostic. Any errors -- replace the drive.