OK. Confirm your P C has successfully updated the microsoft patch. Go to Control Pannel etc and check that the update has been succesfully installed my (borrowed) Win 8.1 PC failed to install a KB.. last friday and I only successfully installed the update on Sunday.
The next port of call, your Router can you let the PPruNe illumni know the details please and any relevent info... e.g Firewall Status/Type and any unique settings etc - Are you running Norton ?
NB BT are progressively updating their firmware on their Home Hub routers to counteract a potential internal net i.e. within your home network, vunerability, re the heart bleed open SSL exploit.
Try re setting the router by switching off leaving for a minute or too and then switching it back on and leaving it to re-establish your connection.
Try another browser. Are other P.C's/phones OK on the network. [Edit: Ignore I mssed you comments.]
Is your PC Wi-FI still working - try the usual windoze checks on your hardware. Does it have a thumb switch to disable the Wi-fi (Dell Vostro ??? ) -If you can see your intranet Wi-fi is OK -Re the IP addressing - This could be a hardware problem or DNS. If the domain is local: will DNS be needed, the internal IP address packets will be routed directly ? I think.
I was wrong re DNS See Here:
http://www.techrepublic.com/forums/q...ranet-iis-dns/
Whoops
Lots of possibles..... [Edit: I missed your 2nd post - try a direct eithernet connection via a cable to your router]
CAT III