If you ever formatted your drive and are stuck without the ability to restore Win 8. the following points might help you to install windows 8 again
1) if you can get your hands on any 8 disk (doesn't matter if its Professional or the Regular version) and install it, your serial key for Win 8 is hardcoded into your motherboard BIOS. Therefore, if you have access to a disk, you can simply install and it will auto activate and install your pre installed key.
2)If you don't have an external DVD Drive, simply download the Win7 to USB tool from Microsoft (it will work for Win 8) and transfer the disk image to a USB thumb drive (from another PC of course). Then boot from the thumb drive to install. Note: You will have to go into the BIOS to turn off UEFI and allow it to boot and install from a thumb drive.
3) It is advisable to switch from UEFI to legacy mode . Then save and exit and allow to restart. Upon restart, enter the BIOS once again and you should now see your thumb drive appear on the list of bootable devices (the thumb drive has to be connected before booting into BIOS). Move the thumb drive up the list to be the first boot device, save and exit and you are in done.