Final answer:
To fix Error LNK2001 unresolved external symbol mainWCRTStartup, check and correct your project settings to ensure the right application type and entry point are configured, such as 'main' for console applications or 'WinMain' for Windows applications.
Step-by-step explanation:
The Error LNK2001 unresolved external symbol mainWCRTStartup typically occurs when a C++ program is being compiled, and the linker cannot find a proper entry point. This is usually because the project is not correctly configured as a console or a Windows application. To fix Error LNK2001, make sure that your project settings are correct for the type of application you are building. If it is a console application, the entry point should be main, while for a Windows application, it should be WinMain. Also, verify that the correct subsystem and entry point are set in the linker settings of your project properties.