The following approach did work for me. I got there via the link in https://stackoverflow.com/a/39113943/4533188

1. Got to https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/
2. Click on the newest version (e.g. 8.1.0)
3. Click on x86_64-posix-sjlj
4. Download the 7z-Archive

Alternative way of clicking around:

1. Got to https://sourceforge.net/projects/mingw-w64/
2. Click on files
3. Click on x86_64-posix-sjlj of the version you want
4. Download the 7z-Archive

Then:

5. Unzip the archive
6. Inside it there is the folder mingw64 - move it (and its contents) into C:\MinGW64
7. The gcc can be found at C:\MinGW64\mingw64\bin\gcc.exe

mingw-w64 is an open source project and the developers provide source code only. If you're looking for Windows binaries then you need to download them from a third party who builds the source.

There are a few configurable options when building the source (such as threading backend and exception-handling backend) so you will see some differences amongst these builds. Here are some options:

• https://stackoverflow.com/questions/30069830/how-to-install-mingw-w64-and-msys2 -- this is the easiest way for installation with ongoing upgradability and support packages. Note that once it is installed you do not need to invoke msys2 to use the compiler , it is possible to just use msys2 for the package manager.
• https://stackoverflow.com/questions/38335424/how-to-use-mingw-64-with-qt-creator
• https://stackoverflow.com/questions/36972968/how-can-use-mingw-w64-and-msys2-with-any-ide-like-eclipse-or-codeblocks
• Official site . If you go here and follow the "mingw64-builds" link then here are some more relevant posts:
  • https://stackoverflow.com/questions/29947302/meaning-of-options-in-mingw-w64-installer
  • https://stackoverflow.com/questions/60210917/how-to-install-minwg64-non-of-the-approaches-work
• nuwen. This is actually mingw-w64 although the guy calls it "mingw" .
• TDM-GCC
• Equation - includes OpenMP

Here's another, slightly different, set of instructions to install zip for git bash on windows:

1. Navigate to this sourceforge page
2. Download zip-3.0-bin.zip
3. In the zipped file, in the bin folder, find the file zip.exe.
4. Extract the file zip.exe to your mingw64 bin folder (for me: C:\Program Files\Git\mingw64\bin)
5. Navigate to to this sourceforge page
6. Download bzip2-1.0.5-bin.zip
7. In the zipped file, in the bin folder, find the file bzip2.dll
8. Extract bzip2.dll to your mingw64\bin folder (same folder as above: C:\Program Files\Git\mingw64\bin)

I got same error and solved it, after struggling a few hours. You should download MinGW64 via https://winlibs.com/#download-release.

After downloading, You should unzip mingw64 file to a folder(in my case I unzipped it to c disk; C:\mingw64)

And then you have to set up path. for that follow below steps;

1. open settings.
2. Search for Edit environment variables for your account.
3. choose path variable and then select edit.
4. Select New and add the Mingw-w64 folder path(bin folder). In my case, I added (C:\mingw64\bin).
5. Select OK to save the updated path. And reopen your cmd, then check if everything is good by typing; gcc --version