Grub rescue error or How do I solve "error: no such partition. Entering rescue mode-grub rescue>"?

I suggest to know few things before solving the problem:

Problem occurred because you deleted the partition(the OS partition) where the grub was located , the Grub(Grand Unified Bootloader) which was managing your boot entry of both OS for example Windows and ubuntu , now if you are deleting it before managing it ,then definitely you will face the error (Grub rescue).

Now we move to the solution: 

(The solution is regarding windows ,I mean after deleting linux you want to recover your old windows OS then follow this) 

I had this issue with my windows 8.1 and  Ubuntu .

I solved it successfully!!

Follow this steps :

1) Remember to insert usb or cd containing Os or iso image of windows 8.1/any other.

(If you dont have the OS CD then use Pendrive as a bootable drive).

for more info how to boot the os to pendrive read my answer from the below link:

How to make the OS bootable pendrive 

2) You have to insert your bootable usb before restarting the pc , after restart 

press Esc button, Now You will see menu

• Select Boot options by f9 button in hp laptops
• Select usb drive
• U will be prompted to windows screen
• Select Repair computer option
• Select troubleshooting or similar options
• 1) Now from the menu list select the ‘Command Prompt’ option.
• 2) At the prompt type the following commands:





     bootrec.exe /fixmbr    
      bootrec /fixboot
     bootrec /rebuildbcd
     1st command is important.
     Press enter and type exit
     Again enter. Close it.. Press on Continues to windows 8.1.