Yup, I guess you are trying to compile a console application and have used main(), however the project is set up as a Win32 Application and is looking for the windows entry point WinMain().
What include file did it specify? Does this file exist in the include directory of the compiler or listed amongst the directories to use for the include files within the IDE?
I’ve only known this type of problem to occur when the compiler doesn’t know where the file is or the file really isn’t there.
Maybe you took an example from a different operating system that has a special set of header files like unix and unistd.h for example.