netsh.exe winsock reset
netsh is a command line shell interface to access network functions.
winsock is an application interface that allows easy access to functions that allow applications to send data over a network. Most often now over the internet via (TCP/IP)
When the reset command is run it will remove all of the third party winsock providers and restore the Microsoft winsock provider to a known state. It would be useful if malware installed its own winsock provider, or you have installed a old 3rd party winsock version.
https://technet.microsoft.com/en-us/library/cc753591(v=ws.10).aspx#BKMK_3
It is kind of a generic command to get your machine to a known state in the hopes that it fixes the problem with out having to really figure out the problem. There are better ways to figure out winsock problems.
when debugging network problems you always want to update the motherboards network drivers and remove any packet injectors before you spend too much time looking at winsock problems.
note:
netsh.exe winsock show catalog
will show a lot of info on all of the transports that winsock runs on top of.
if you do a reset, you might have to reinstall some of these by actually reinstalling the transport
(like reinstalling your Bluetooth to get it to work correctly again)