Microsoft seems to have made a right pigs ear of backing up an 8.1 system, however you could try this click here. It seems even worse if you upgraded from 8 to 8.1 as it appears that it restores to 8 and you have to go through the update procedure all over again.
As others have suggested here its much easier to use a third party backup utility such as the free version of Macrium Reflect. I use Acronis TI and back up my C: drive using that then in the case of problems its simply a case of restoring from the backup. Just done it today. Dont forget to use the option to create a bootable recovery disc.