set directory for swap files on Windows

vimrc

@@ -70,6 +70,10 @@ else
     set scrolloff=4
 endif
 
+if has("win32") || has("win64")
+    set directory=$TMP
+end
+
 " mappings
 map ,# :set paste␍O75A#yypO#73A A#0ll:set nopaste␍R
 map ,p :set paste␍o#73A A#0ll:set nopaste␍R