diff --git a/scheme/httpd/surflets/TODO b/scheme/httpd/surflets/TODO
index c07c1be..f79b559 100644
--- a/scheme/httpd/surflets/TODO
+++ b/scheme/httpd/surflets/TODO
@@ -5,3 +5,6 @@
 * use internal-error, if surflet fails, not bad gateway
 * don't let callback-functions return.
 * use another name for callback-functor.
+* tell in howto how to start in cygwin environment.
+  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Wins\Parameters
+