For those wondering, when using the biggest QR code with the maximum error correction (10,208 bytes), 1,454,942 QR codes is slightly less than 14GiB, which should be more than enough for a Windows ISO.
My math: (1454942×10208)÷1024÷1024÷1024≈13.83
Edit: Damn another guy beat me to it, now I wonder how I’m so far off.
Because the other comment had a useless counterproductive step in it, namely base64.
Maybe, but also I think I was looking at the raw ‘data bits’, not ‘binary’ data. It’s actually almost exactly 4GiB, even when dropping down to minimum error correction (1.7 GiB otherwise).
(1454942×2953)÷1024÷1024÷1024≈4.00
Edit: So if alphanumeric mode could store lowercase letters, base64 would’ve stored more.