Sorry for late answer, I was on summer vacations. I used wxWorks 2.8 library that is very compact (2Mb resulting size of a statically linked executable) and also wxWorks depends on Win32 API only, no OpenGL, ANGLE, etc. (compare with Qt 5.x).
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What GUI library did you use to create pure Win32-API standalone app without external dependencies?
Sorry for late answer, I was on summer vacations. I used wxWorks 2.8 library that is very compact (2Mb resulting size of a statically linked executable) and also wxWorks depends on Win32 API only, no OpenGL, ANGLE, etc. (compare with Qt 5.x).