fixes from compiling code and running all the tests on NT
diff --git a/src/libFLAC/metadata_iterators.c b/src/libFLAC/metadata_iterators.c
index 46968c4..c67a573 100644
--- a/src/libFLAC/metadata_iterators.c
+++ b/src/libFLAC/metadata_iterators.c
@@ -2134,6 +2134,15 @@
 
 	(void)fclose(*tempfile);
 	*tempfile = 0;
+
+#if defined _MSC_VER || defined __MINGW32__
+	if(unlink(filename) < 0) {
+		cleanup_tempfile_(tempfile, tempfilename);
+		*status = FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR;
+		return false;
+	}
+#endif
+
 	/*@@@ to fully support the tempfile_path_prefix we need to update this piece to actually copy across filesystems instead of just rename(): */
 	if(0 != rename(*tempfilename, filename)) {
 		cleanup_tempfile_(tempfile, tempfilename);