Why does Visual Studio 2013 error on C4996?

In previous versions of Visual Studio using functions like _sleep or strncpy just outputs a warning. In the latest version, it's suddenly an error:

error C4996: '_sleep': This function or variable has been superseded by newer library or operating system functionality. Consider using Sleep instead. See online help for details.

I know I can disable it by adding #pragma warning(disable: 4996) in the beginning of the code, but it's extremely annoying that VS is trying to force me to use other functions. Is there any way to disable this behavior?

Before you ask, "Treat Warnings As Errors" is disabled, and it errors even if I turn off all warnings!

Apparently new projects enable "SDK check" by default now, which treats these warnings as errors. To disable it, go to project properties -> Configuration Properties -> C/C++ -> General -> SDL checks -> No.

enter at the beginning of the program:

#pragma warning(disable : 4996)

and that's it.

You can also disable specific warning numbers in C/C++ > Advanced > Disable Specific Warnings.

Just to add to this, _CRT_NONSTDC_NO_DEPRECATE worked for me in VS2019. _CRT_SECURE_NO_WARNINGS alone did not clear this for me (I have both defined).

Similar to the other answers, this may be added by right-clicking the project in Solution Explorer, Then going to Properties->Configuration Properties->C/C++->Preprocessor->Preprocessor Definitions->Edit... then adding the line _CRT_NONSTDC_NO_DEPRECATE.