how to download c++ portable compiler

Open your web browser and go to the MinGW-w64 download page: https://mingw-w64.org/doku.php
Click on the "Downloads" link in the navigation menu.
On the Downloads page, find the section titled "Toolchains targetting Win32" and click on the link that says "Personal Builds."
Look for the version that suits your system architecture (32-bit or 64-bit). Click on the link corresponding to your preference.
On the next page, you'll see a table with various versions of the compiler. Click on the version number to proceed to the download page.
On the download page, find the table entry with the architecture you need (i.e., Win32 or Win64) and click on the link under the "Release" column to download the installer.
Once the installer is downloaded, run it to start the installation process.
In the installer, choose the components you want to install. Typically, you'll need at least the "Basic Setup." You can also customize the installation by selecting additional components if needed.
Set the installation directory according to your preference. The default directory is usually fine for most users.
Choose the architecture for the compiler. If you are on a 64-bit system, it's recommended to choose the 64-bit architecture.
Set the thread model. The default "posix" thread model is usually suitable for most users.
Click the "Install" button to begin the installation process.
Wait for the installation to complete. Once finished, you'll see a summary screen indicating a successful installation.
Add the bin directory of the MinGW-w64 installation to your system's PATH environment variable. This step is essential for the compiler to be accessible from the command line.
Open a new command prompt or terminal window and type "g++ --version" to verify that the installation was successful. You should see information about the installed compiler version.

Now you have a portable C++ compiler installed on your system using MinGW-w64.