@abhishekku14745 sounds to me like you lost your boot drive. I would try and access the BIOS and check if the BIOS can "see" your drive. If it can, it is possible that your OS got corrupted and may need a reinstall. If it does not see it, then it is most likely a failed drive. To get into it, press F2 at the boot splash screen to enter the EFI setup. Look around and see if you can find your drive. Check for Boot order etc.
You want to set your boot order to a USB drive. You will have to make a USB drive bootable and use that to start your computer, then try to restore your drive with that. Since you did not tell us which OS (I assume Windows x.xx) we will have to wait to see what you discover.