Asus PCE N15 unable to connect.

My roommate has a custom desktop PC, which runs Windows 8 x64.
It can't connect to the internet, or the local network. Windows says limited connection, but ping the router IP yields only lost packages. Solving the error with the automatic error solver, displays problems with the DNS.
The roommate says the connection has worked for a limited time, for about a 1/2 hour, but fell out from time to time.

He has tried to connect to our wireless router, a wireless n d-link dir615.
It is set to WPA/WPA2 with AES cipher and PSK.
The router runs the newest firmware available, which gives no issues for any other device in the house. (Including Iphones, android phones, old and new N-capable, and N-incapable laptops and desktops).
His PC has an almost unused Asus PCE N15 wireless adapter installed.
He says it worked on a different network (He just moved in).

I have tried to give him a static IP and dns, both in windows, and get the router to assign one to him.
I have tried to give him an alternative DNS, e.g. OpenDNS.
I have tried to update his drivers, both the ones provided from Asus, but also one from realtek, since the NIC has a realtek chip on it.

I have no ideas left for what the problem might be, other than the NIC somehow have faulted, or suddenly is incompatible with WIN8.

English is not my native language, so please look past any weird phrasing, or grammar errors.

Check properties on the wireless driver. Could be some firewall from anti-virus blocking connection , or some check mark somewhere it shouldn't be. Uncheck IPV 6 and check those settings nearby