Occassionally, Windows 7 has a tendency to automatically create an excessive amount of various tunnel adapters, ranging from isatap, 6to4 and Teredo. The result is a slowdown during startup because of all the interfaces, and ifconfig's output gets cluttered.
You can manually remove the interfaces through Device Manager. Start it up (run devmgmt.msc), then turn on hidden devices:
Under Network adapters, you'll find the whole list of adapters, starting with Microsoft 6to4 Adapter or Microsoft ISATAP Adapter, followed by a number. You can manually delete ("uninstall") all but the unnumbered adapters.
There are also ways to automatically uninstall these adapters, which is recommended if you have a lot of them. It involves using a command-line tool called devcon, which allows manipulations of devices through CLI. This link contains a helper program to help you remove the adapters using devcon. Note that for this to work, you need to download and install devcon: download at Microsoft KB 311272.
With normal use, you have no need for these special adapters, or its creation. You can turn off this through netsh via the command prompt.
netsh int teredo set state disabled netsh int 6to4 set state disabled netsh int isatap set state disabled
This disables the use of these adapters and its automatic creation.
If you ever need to re-enable one or more tunnel protocols, run one or more of these in a command prompt:
netsh int teredo set state default netsh int 6to4 set state default netsh int isatap set state default