If you're sharing sensitive business communications via a public network, a virtual private network (VPN) is essential. Windows 8.1 and Windows RT will add support for a wider range of VPN clients, and apps will be able to launch VPN connections automatically. In addition, Windows will prompt you to sign in when you choose an app or resource that needs VPN access. Certainly, auto-triggered VPN is a nice addition. But will it boost the business appeal of Windows RT, which hasn't generated much interest from corporations, consumers or even Microsoft's OEMs?