your PC needs to be repaired
The operating system could not be loaded because a required file is missing or contains errors
You will need to use the recovery tools on your installation media.
Sounds like you developed a hardware problem, perhaps RAM or HDD failure. However, try repairing Windows 1st.
Boot from your Installation disk and choose Repair. On the Troubleshoot Menu choose Refresh your PC.
If you bought a retail or system builder version of W8, you should be able to put the Windows disc in like you are going to install the OS, but there will be an option to "Repair my system" ( or something similar to that ). Try that first, otherwise you may have to re-install.
If you have an SSD and you are going to try installing again, you might want to try deleting the volume ( un-formatting ) first on another computer ( in an external drive ) and then re-install it and let the Windows 8 disk format and install the boot partition and the OS all in one step. Normally it is not necessary to have an un-formatted drive, but it seems some SSD's work better when the Windows install disc does all of the operations for you.