Grub boot nightmare

Hello forums,
I recently successfully installed an Ubuntu/Windows 8.1 dual-boot, however soon stripped the Ubuntu partitions using Partition manager in Windows. I accidentally rebooted my system while faffing around in some advanced options and am now stuck in GRUB without means of a rescue drive. Any help would be much appreciated,

Ben

Do you not have any external bootable media for your system? Do you have any way of getting some version, possibility even a Windows 7 or the 8.1 Enterprise version so you can make a bootable DVD or flash drive?

Did you install Ubuntu as a Legacy install, or a UEFI? Have you tried using the Bios to set the Windows Boot Manager as primary boot device, or use a Boot Device Menu to see if there are options other than the GRUB?