I have suffered this after lending my laptop.
Follow this to see if this helps.1 Start
2 control panel
3 Network and internet
4 Network connections , RIGHT click on internet connection not your home connections the one with the red x in it or the one you are trying to connect to.
5 Double click on internet protocol version 4 (tcp /ip v4)
6 click the radio button (obtain an IP address automatically) and click the radio button for obtain a DNS server number automatically. You can also look at the same place for all your connections, Ethernet or Wi Fi. Should be the same.
Some people like to have a static IP and do this
Good luck
Alton