Windows 8.1 can't connect to NAS

I've setup a NAS File Server over my Fritz!Box 7390.

Windows XP and Debian can mount it easily, however windows 8.1 cannot.

I can see my NAS in my Network Tab in the Windows Explorer, however it's listed as "Other Device" and clicking on it simply opens the configuration page of my fritzbox (it's a wlan router).

When I manually enter the IP of the NAS it says it cannot connect to it (Error code: 0x80070035).

Windows diagnostic tools won't find anything, as always, and I srsrly don't know what else to do.

Go to the adapter settings and check to see that on the properties of the adapter, that "Client for Microsoft Networks" is installed. This is in the list that contains Internet Protocols. This was missing from my adapters, took 10 seconds to add it in and reboot, then everything was fine.