# Including the Intel® Visual Fortran Interface Definitions for Windows* API Routines

This topic only applies to Windows*.

Intel® Fortran provides interface definitions for both the Intel Fortran library routines and most of the Windows* API routines in the standard include directory. Documentation on the Windows API can be found at msdn.microsoft.com.

To include the Windows API interface definitions, do one of the following:

1. Add the statement USE IFWIN to include all Windows API routine definitions.

   The USE IFWIN statement makes all parameters and interfaces for most Windows routines available to your Intel Fortran program. Any program or subprogram that uses the Windows features can include the statement USE IFWIN, which is needed in each subprogram that makes Windows API calls.

   Add the USE statement before any declaration statements (such as IMPLICIT NONE or INTEGER).

2. You can limit the type of parameters and interfaces for Windows applications to make compilation times faster. To do this, include only the subsets of the Windows API needed in multiple USE statements (see the file ...\INCLUDE\IFWIN.F90).

   To locate the specific libraries for the routines being called, view the QuickInfo at the bottom of the routine page in the Windows API documentation at msdn.microsoft.com, which lists the import library name. For example, to call only GetSystemTime, you need the interface definitions provided in kernel32.mod (binary form). To do this, add the following USE statement:

       USE KERNEL32

If you want to further minimize compile time, add the ONLY keyword to the USE statement. For example:

    USE KERNEL32, only: GetSystemTime, GetLastError

Parent topic: Using the Windows* API Routines