First start with the basics;
type ncpa.cpl into the search or run dialog box and hit enter
select then right click your network adapter and choose properties
In the center frame labeled "This connection uses the following items"
Make sure everything present is checked (for now)
and OK your way back out of there.
Now type services.msc into the search or run dialog box and hit enter
Scroll and make sure the following two services are started and set to automatic, if not double click and change
Server
Workstation
There are several others that you may need to also adjust and or startup, but without the server service running you may have the symptoms you are describing