Well, here's how you can sort yourself out (shamelessly adapted from the always awesome and extremely comprehensive Arch Linux documentation):
- Download the latest rEFInd CD-R image from here.
- Extract the ISO and use Rufus to create a bootable USB drive. Make sure that, when you create the USB, you have "GPT partition scheme for UEFI computer" selected, under "Partition scheme and target system type".
- Boot your computer in UEFI mode, and enter the EFI BIOS to select the USB as your boot device
- On the rEFInd screen select "Start EFI shell".
- At the
2.0 Shell >prompt type:
bcfg boot dump
This should confirm that some of your old entries have been unceremoniously wiped out by Windows.
- Find the disk on which your old EFI partition resides by issuing something like:
NB: you can use the
mapcommand to get a list of all the disks and partitions detected during boot.
- Once you have the proper
fs#information (and provided you want to add an entry that boots into a rEFInd installed on your EFI system partition under
EFI\refind\refind_x64.efi), issue something like:
bcfg boot add 0 fs0:\EFI\refind\refind_x64.efi rEFIndNote: If needed you can also use
bcfg boot rm #to remove existing entries.
- Confirm that your entry has been properly installed as the first option, by re-issuing
bcfg boot dump. Then remove the USB, reset your machine, and you should find that everything is back to normal.