Defined _WIN32_WINNT in the project properties to be 0x0600 (i.e. Vista). (Note: DLLs may still have code that requires 7+ functionality.) Cleaned up throw_helpers and made it so that Windows-specific helpers are only included if _WIN32_WINNT is defined. Added a timer class to get proper elapsed time values. Fixed up the sample draw code so that it works with the (now correct) elapsed time value passed to it.