Ok first of all, did you buy this ESC from rcbonezzz or rcwaffle? I saw today that he's put up a few MMs for sale, thats why I ask. Secondly, run a firmware update from Castle Link and see what happens. Also, I'm not sure if there are any Vista specific issues as I'm a linux user but read the Castle Link specific threads. And I hope you did disconnect the battery from the ESC before hooking it up to the ESC.