Use an official ISO or accept that the minimum realistic size is ~1.5 GB after heavy, unsafe modifications — not 10 MB.
A full Windows 7 Ultimate 64-bit installation ISO is roughly (3,000–4,000 MB). Compressing an OS to 10 MB would require removing 99.7% of the files, making it impossible to boot, install, or run. Windows 7 Ultimate 64 Bit Highly Compressed 10mb -FREE-
Even a stripped-down “Lite” version (like Tiny7 or Windows 7 Lite) cannot go below after extreme reduction — and those are already unstable and unsafe. Use an official ISO or accept that the