Qt-opensource-windows-x86-5.15.2.exe
Once installed, let us verify the toolchain works. Create a simple file, main.cpp:
#include <QApplication> #include <QLabel>
int main(int argc, char *argv[]) QApplication app(argc, argv); QLabel label("Hello from Qt 5.15.2 on Windows x86!\nThis is a 32-bit executable."); label.resize(300, 100); label.show(); return app.exec();
To compile without Qt Creator (using command line for clarity):
REM Set up environment (adjust path to your installation) C:\Qt\5.15.2\mingw81_32\bin\qmake -project C:\Qt\5.15.2\mingw81_32\bin\qmake mingw32-make
REM Run the output release\myapp.exe
Use a tool like Dependency Walker to ensure no stray 64-bit DLLs are linked. The output .exe should report "32-bit" in Task Manager. qt-opensource-windows-x86-5.15.2.exe
Even with a successful install, you might hit these issues:
| Error | Cause | Fix |
| :--- | :--- | :--- |
| The program can't start because VCRUNTIME140.dll is missing | You used MSVC build but lack C++ Redistributables. | Install vc_redist.x86.exe from Microsoft. |
| Cannot find -lssl | Missing OpenSSL libraries. | Copy libeay32.dll and ssleay32.dll (or libcrypto-1_1.dll and libssl-1_1.dll) to your build folder. |
| QWidgets: No such file or directory | Kit points to wrong Qt version. | Re-run Qt Creator's Kit configuration. |
| Fatal error: g++.exe: CreateProcess: No such file | Antivirus (McAfee, Norton) quarantined MinGW. | Add C:\Qt as an exception in your antivirus. | Once installed, let us verify the toolchain works
Downloading the file is easy (archive.org and Qt's official archive store older versions). Installing it correctly requires attention.
Since 2021, the official online installer for open-source Qt requires a Qt Account login. qt-opensource-windows-x86-5.15.2.exe predates that strict requirement, allowing anonymous offline installation. To compile without Qt Creator (using command line