In most cases the error message appears due to hard drive failure. The system is trying to boot from network since it is unable to detect the hard drive and thus showing the error message regarding PXE
To confirm, restart the system and press F2
during startup to access CMOS setup utility (you need to repeatedly tap F2 after turning on the system)
(The exact key combination to enter CMOS setup may differ for your system. If F2 does not work, try F1
See if the hard drive is listed in the first page. If the system is able to detect the drive, it will show the model number of the drive, and in some system, its capacity.
If you do not find the model number of the hard drive OR it shows None (or Not detected) beside hard drive model name then the system failed to detect the hard drive.
If the hard drive is not listed, you can try the following steps to reset hardware once:
1 Disconnect the battery and ac adapter (if connected). If there is any devices connected to any of the USB ports, disconnect the same.
2 Wait for 10 minutes
3 Press and hold down the power button for 30 seconds and release power button
4 Reconnect the battery and charger, and turn it on
5 Once the system starts, repeatedly tap F2
key to enter CMOS setup
6 Then press F9
to load default settings
7 Press F10
to Save and Exit setup
If it remains same, then the problem is with hard drive. In that case you need to replace the hard drive.