Is there any offline QR code creation or generation software with selectable error correction level? I have kept looking, but almost all the ones I see are online.
Can't help with windows but linux has QtQr. Works great.
I wouldn't feel safe generating and printing private keys in windows anyway though. Just get a usb flash drive and put some bootable linux on it, and boot from there.
And maybe unplug your sata cables if you're real paranoid.