My Techy Chap says -
Sounds like he has some serious malware issue's.
Start up in "safe mode with networking". To get the options for this on screen he needs to repeatedly press F8 when switching the PC on.
If internet then allows him to connect in safemode, tell him to download and run this one time scanner from Malwarebytes. The web address is http://www.malwarebytes.org/products/mbar/
Hopefully that will help. If he still cant access the internet in safe mode either, then downloading the above and using a memory stick would work to get it onto the required pc from a working one.
No guarantees, but this is how I would personally go at it before looking into anything else.
I've been using Malwarebytes with Microsoft Security Essentials for a few years, on his recommendation, with no issues at all.