Updated Compiling from source (markdown)

Compiling-from-source.md

@@ -88,6 +88,33 @@ Windows compilation using Visual Studio is not supported. Mingw64 is
 used on a Linux system (bare metal or virtual machine) to cross-compile
 cpuminer-opt executable binaries for Windows.
 
+cpuminer-opt can now be built on Windows for windows using MinGW-w64 and MSYS2.
+Windows 7 or newer is required.
+
+1. Download and install the latest version of msys2-x86_64 from https://www.msys2.org/
+
+2. Install the following additional packages
+
+$ pacman -Su autoconf libcurl-devel mingw-w64-x86_64-curl gmp-devel jansson-devel openssl-devel zlib-devel
+
+3. Set environmewnt variable to allow cpuminer-opt to be run from a Windows terminal, otherwise it can only run from an MSYS2 terminal.
+
+https://stackoverflow.com/questions/6951938/libgmp-10-dll-is-missing
+
+4. Open "MSYS2 MinGW-w64" from the Windows start menu.
+
+4. Download and decompress cpuminer-opt source code to your MSYS2 home directory, usually c:\msys2\home\[windows user]\ or a directory of your choice.
+
+5. Open "MSYS2 MinGW-w64" from the Windows start menu and change directories to the downloaded cpuminer-opt and compile.
+
+$ ./build.sh
+
+6. Run cpuminer.exe directly from an MSYS2 terminal or, if step 3 was performed above, a Windows terminal on the same system.
+
+## Building for Windows, the hard way
+
+This procedure is used to build the Windows binary release package and is done from a Linux environment.
+
 These instructions were written for Debian and Ubuntu compatible distributions
 but should work on other major distributions as well. However some of the
 package names or file paths may be different.