You're looking for a Fortran 77 compiler for Windows 10 64-bit that you can download for free. Here are a few options:
GNU Fortran (gfortran) : The GNU Fortran compiler is a popular, widely-used, and free compiler that supports Fortran 77. You can download the 64-bit version for Windows 10 from the official GNU website:
https://gcc.gnu.org/fortran/download.html Specifically, you can download the latest version of gfortran for Windows from the MinGW-w64 project:
https://sourceforge.net/projects/mingw-w64/files/ fortran 77 compiler for windows 10 64-bit free download
Follow the installation instructions to install gfortran on your Windows 10 system.
Silverfrost FTN95 : This is a free Fortran 95 compiler that also supports Fortran 77. It comes with a comprehensive development environment, including a code editor, debugger, and project manager.
https://www.silverfrost.com/ftn95.html You can download the free Community Edition, which is suitable for non-commercial use. You're looking for a Fortran 77 compiler for
Intel Fortran Compiler (ifort) : Although not a traditional Fortran 77 compiler, the Intel Fortran Compiler supports Fortran 77 and is available for free on Windows 10 64-bit.
https://software.intel.com/content/www/us/en/develop/tools/oneapi/components/fortran-compiler.html You'll need to create an Intel Developer Zone account to access the free download.
Open64 : This is another free, open-source Fortran compiler that supports Fortran 77. Silverfrost FTN95 : This is a free Fortran
https://open64.net/ You can download the Windows 64-bit version from the Open64 website.
Before downloading and installing any of these compilers, make sure to check the system requirements and any specific installation instructions for each compiler. Once you've installed a Fortran 77 compiler, you can start writing, compiling, and running your Fortran programs on Windows 10 64-bit!