Index: PC/_winreg.c
===================================================================
--- PC/_winreg.c	(revision 76116)
+++ PC/_winreg.c	(working copy)
@@ -1302,6 +1302,9 @@
 		return PyErr_SetFromWindowsErrWithFunction(rc,
 							   "RegQueryValue");
 	}
+    if(*retBuf == 0 && bufSize == 0)
+        return retStr;
+
 	_PyString_Resize(&retStr, strlen(retBuf));
 	return retStr;
 }