How to uninstall Hyper R2 2012 Sever W/O BACKUP

Okay, I downloaded Hyper-V R2 2012, I thought it was like a software such as VM-Player and VirtualBox. But it wasn't and altered my Operating System completely, and now I'm stuck on logging into Hyper V R2 2012 Server whenever I start it up. In there it has a small window which lets you type in commands, for example "12" for restarting and such cases. I tried to use backup, but I don't have the iso file of Windows 8, nor can I use any methods to backup because I cannot save my data to a disc after Hyper-V is installed/booted up. 

Is there any way to restore my OS to windows 8.1 again? Or reverting it back to orginal state without the backup? Or maybe even is there a way to backup the laptop THEN use it to restore the Windows 8.1 Version?? I really want to uninstall Hyper-V and have back my old OS! Please help and thanks!