Hi siftekhar,

Would like to know the primal issue that you are experiencing. I may be able to help you resolve it without the restore options. However, if you still intend to do a factory restore you may find the following steps useful. 

It appears that you are not able to boot into the operating system. In that case, you may try to crash your system 3 to 4 times to access Advanced Recovery Options. For crashing Windows 8 system, you may power off the system while it is trying to load Windows OS (i.e. at Dell logo when the circling dots appear) by pressing and holding the power button down till the computer powers off.

However, If you are able to boot into the operating system, you may follow the steps below to take the laptop back to factory settings i.e. day one when you purchased the laptop using Dell Backup and Recovery.

Note : This step leads to complete data loss if you select the option to Erase files in Step 10

Dell Backup and Recovery can recover the Operating system or backup from the recovery partition. To recover the OS from the recovery partition, follow these steps:

1. Plug in the AC adapter.
2. Power on the laptop. 
3. Click on Power button on right hand side bottom corner of the screen.
4. Press and hold the Shift key on the keyboard and click Restart from the options provided. 
5. Click Troubleshoot from the options onscreen after restart.
   
   
   
   
   
   
   
6. Click the Dell Backup and Recovery icon.
   
   
   
   
   
   
   
7. The system restarts and comes back up, click Next on the Dell Backup and Recovery Screen. 
   
   
   
   
   
   
   
8. The system would be checked to see if the smart repair option can fix the issue, click Next once this is done. 
   
   
   
   
   
   
   
9. You will be prompted to select the backup to be used, click the factory image option or select from one of the backups. Click Next. 
   
   
   
   
   
   
   
10. You will be prompted to backup your files, if needed do so by selecting the option Yes, backup my personal files (Make sure to have an external backup hard drive handy.) or select No, Erase my files. 
    
    
    
    
    
    
    
11. The system goes ahead and completes the restore of the operating system. Click Restart when prompted. 
    
    
    
    
    
    
    
12. Follow the on-screen instructions to setup the system with windows.

If the above options, does not work, you might need to install the windows 8 manually using the recovery discs with the help of an external USB optical drive.

Hope this helps. Please reply if you have any further questions.