Kindly follow the below mentioned steps in order:
1.Confirm Hard Drive is recognized in BIOS. If yes, follow next step. If NO, load BIOS defaults.
2.Boot to Safe mode and perform system restore. System Restore will affect Windows system files, programs, and registry settings only. If system restore fails or unable to access safe mode, follow next step.
3.Run Start Up repair from the URL mentioned: http://windows.microsoft.com/en-GB/...
4.If the issue still persists, then try running the Hardware Diagnostics. In order to run Dell Diagnostics, follow the mentioned steps: Restart your computer. When the DELL™ logo appears, tap <F12> immediately. In the boot device list, highlight Boot to Utility Partition and press <Enter>. Under Dell Diagnostics Main Menu (see Dell Diagnostics Main Menu), select the extended test. If you get any error code, make a note of the error code.
Let me know the Results
Thanks & Regards