Hi Conor,
Thank you for posting your query in Microsoft Community and giving us opportunity to assist you.
As per the description, you are facing issues with Windows network diagnostics and receiving error message saying “Your computer appears to be correctly configured, but the device or resource (www.microsoft.com) is not responding”. To help you suggest steps to resolve the issue, I would appreciate if you could answer the following question:
Have you made any changes on the computer prior to the issue?
To troubleshoot this problem, try one or more of the following methods.
Method 1: Restart the router
Remove the power cord from the router. After all lights on the router have gone out, wait at least 10 seconds, and then reconnect the power cord to the router.
Method 2: You can reset the TCP/IP stack from the Command Prompt. Follow the steps.
a. Press Windows +X.
b. Click Command Prompt(Admin mode)
c. Type ‘netsh int ip reset c:\resetlog.txt’
d. Press Enter.
e. Reboot the computer.
Method 3: I would suggest you to perform the following methods and check if it helps to resolve the issue.
a. Press ‘Windows + W’ key on the keyboard.
b.In the search box, type cmd then click Run as administrator
c. At the command prompt, type the following:
ipconfig/release
ipconfig/renew
ipconfig/flushdns
d.Exit the command prompt
e.Press ‘Windows + W’ key on the keyboard.
f. In the search box, type: %temp% and hit Enter
g. Delete contents of the temp folder
h.Restart your system and try downloading again from the mail you received.
i. If the problems persist, try resetting your router if you are connected one.
j. Power down the router, disconnect it, wait 10 minutes.
k. Reconnect it, power up again
l. Reconnect the Ethernet cable
Hope this information helps. For any further Windows related assistance, feel free to contact us and we will be happy to help.