There are several reasons why you may get this error:
USB cable is not connected properly;
USB cable has been disconnected;
Network settings are not correct; or
Wireless network is not connected properly.
1. Press Windows + R key together to open Run window.
2. Type msconfig in the Run window and press Enter key to open System Configuration Utility window.
3. Go to Boot tab in System Configuration Utility window and check \\\\\\\\\\\\\\\"Safe Boot\\\\\\\\\\\\\\\" option after selecting it from drop-down list under Boot Options section.
4. Click OK button to save changes and restart your Windows PC in safe mode with networking option selected by default on next screen of System Configuration Utility window.
HP laptop Boot Device Not Found Error (3FO) is a common issue. It can occur due to any of the following reasons:
Corrupted or missing system files
Corrupted system registry
Virus or malware infection
Hardware failure
Hard disk failure
If your laptop does not boot anymore, then there is a good chance that the hard drive has failed. If you still have access to the computer when it starts up, go into its BIOS settings by pressing F10 or F12 during startup. Then, look for a menu called Hardware Configuration or System Configuration. Select this option and look for options related to complex drive configuration, such as Configure SATA or something similar. Try changing these settings and see if this helps solve the problem.