Tried to dual boot Arch with Windows yesterday.

Everything was going smoothly. Shrunk the C: partition, ran the installer, installed the OS fine. But it was still booting straight to Windows.

So I edited the BCD to point to Grub instead of Wilndows. Then the plan was to boot into Arch, find Windows, and add it to Grub, problem solved.

Wrong. I had forgotten to disable secure boot. Arch and Grub were booting in BIOS mode, but Windows was UEFI. Grub couldn't boot or even see Windows.

So now I was stuck with just Arch. So I flashed a Windows drive, booted from that, automatic startup repair failed. Opened up the command prompt, tried to rebuild the BCD from there. Surely I can just rebuild it and forget about trying to dual boot right? I just want to get back to being able to use my PC.

Wrong again. Didn't find Windows. Had to get rid of the BCD file before I could rebuild it, but couldn't find it. Found out that I could use diskpart to mount the system partition and assign it a drive letter, renamed the BCD, rebuilt it, and finally was able to reboot into Windows.

Learn from my arrogance. First time Linux users should not attempt to install Arch, let alone do it alongside Windows on the same disk.