I have 2 accounts on my Win 7 64-bit machine. One is an admin account and the other standard. I don't recall under which account I originally installed. But the update was done on the standard account using the admin password. In any event, once I had this problem, I uninstalled and then re-installed under the admin account. I have this problem only when starting sync on the standard account. It starts on the admin account without asking for any password. Also, it appears that the start on the standard account is with a command line to install since when I look at details it has /PERFORMINSTAL