Have you checked the host file on the machine to see if there are local additions overwriting your isp dns servers?
Let’s start here :
# On Windows 10 type '''cmd''' in the search box to open a command console.
# '''ipconfig /all''' – displays more information about the network setup on your systems including the MAC address.
# Then post the results here and we can begin troubleshooting what may be occurring.
cheers!