Have tried reinstall system, and unplugged and plugged in the hard disk, problem remains. Still showing the same message at start.
Besides, no problem for the boot USB disk to find the hard disk, scanning tool shows the hard disk is heathy. I tried to use the disk as a portable disk on another PC, and it was read well.
So what's up with my Dell E5510 laptop plz? During the one years warranty, already changed one LCD screen and two hard disks, and problem happens again after warranty expired. Need urgent help, thanks guys.