Without getting to technical. Teredro tunneling adapter protocol. Is the ability to do ipv6 tunneling over ipv4. It usually is installed by default, but since you had issues you probably reinstalled your nic card and ipv6 wasn't installed. So you go to start, run & type in ncpa.cpl hit enter. This brings up your nic card adapters. If you have both a regualr wired nic and a wifi nic then you need to select which one you're using. Right click the adapter and to go to properties. The list is made up of client/service/protocol.
After pressing the install button you can select which type to install client/service/protocol In your case you want a protocol. After choosing protcol another list opens and you should see IPv6 in there. You select it and press ok/apply. If nothing is listed then you need to download the right driver for your pc.
Typically by default this is what you would see for a regular wired nic card after opening properties....
Client For Microsoft
PC Network Filter Driver
QOS Packet Scheduler
File and Printer Sharing for Microsoft Networks
Internet Protocol Version 6 (TCP/IPv6)
Internet Protocol Version 4 (TCP/IPv4)
Link-Layer Topology Discovery Mapper I/O Driver
Link-Layer Topology Discovery Responder