Thank you for your Dockerfile, @adityapk00! I can confirm that by bumping up the Ubuntu version from ubuntu:18.04 to ubuntu:20.04 the compilation succeeds and the resulting zcashd.exe (compiled from v4.1.1 git checkout) works fine under Windows 7 Enterprise SP1.
I trimmed the package imports to just apt install -y git build-essential curl g++-mingw-w64-x86-64 gcc-mingw-w64-x86-64 libtinfo5 automake libtool bsdmainutils, as the rest seemed to be implied in Ubuntu 20.04 (I guess they renamed python-zmq to python3-zmq in the Python 3 transition but my compilation succeeded even without that…) Are the others necessary/enable features? I noticed that zcashd.exe terminal output did not show the ANSI art logo and maybe that’s enabled by ncurses. Will try to investigate in a bit…
FWIW, compilation under Ubuntu 20.10 fails, as it seems to have a strict tar implementation (clang’s tar.xz archive packs symlinks (e.g. lib/liblldb.so) before the corresponding files (e.g. lib/liblldb.so.8.0.0) so the un-tar-ing step fails with "Cannot change mode to rwxrwxr-x" after tar tries to chmod a bunch of dangling symlinks. But 20.04 is the most stable LTS, and 20.10 was released just last month, so maybe that’s expected.
I have older hardware (esp. laptops) laying around that run Windows 7 just fine and would make for good self-sovereignty ZecWallet full nodes, but Windows 10 (which I have a license for) is simply too slow 
Plus, peer cryptocurrencies like Bitcoin or Monero run fine on Windows 7, so it would be great if ZecWallet could too!