[Dev-C++] What does _WIN32_IE define ?

[Peter S. <p.s...@ut...>]

Hi,

in some system headers, for instance commctrl.h and 
prsht.h are a lot of Constants commented out with
_WIN32_IE . What does the value of  _WIN32_IE
mean and are there any drawbacks if I define it ?

Is there an official  way to define such constants 
globally in the IDE ?

tia, Peter