I had the same exact issue... Try inserting the windows 8 installation disc or OEM disc that came with ur pc. this is what worked for me
For Windows 8:
1 – Boot from repair disc > Choose Keyboard type > click Troubleshoot > click Advanced options > choose Automatic Repair
if that fails then use:
2 -Boot from Recovery disc or Install disc
-Boot from repair disc > Chose Keyboard type > click Troubleshoot > click Advanced options > choose Command Prompt
or
-Boot from Install disc > Click Next > click Repair your computer > click Troubleshoot > click Advanced options > choose Command Prompt
type > bootrec /fixmbr press Enter(writes mbr but does not overwrite partition table)
type > bootrec /fixboot press Enter(writes new boot sector to system partition)
type > bootrec /rebuildbcd press Enter(scans for other OS’s, unlike rebuildbcd it allows you to select the OS’s you want to add to bcd)
after you have entered these commands, close the Command Prompt and Reboot your PC