How to disallow changing DNS server address

We just purchased our first batch of Win 8.1 PCs, but they are not the Pro version, so there is no gpedit. I want to prevent users from accessing the TCP/IPv4 Properties dialog box in order to make sure that the DNS server address is always obtained automatically. I have been looking through the registry but can't find a setting to control that. Suggestions?

Also, I'd love to find a reference guide that defines all the registry settings. Anyone know of one? Thanks.