I spent a lot of time trying to connect my NAS (QNAP 119) to my new Windows 8.1 PC. It refused to map it as a network drive - so I couldn't access it in Wondows Explorer.
I could access the NAS via my Web Browser, and it aperad in Windows Explorer as a media station (I think it uses Twonky)
On my Vista PC - having Zone Alarm Free installed, I had not this problem.
Solution was to disable the ZoneAlarm firewall.
However, since I want to use it, I am not sure how to configure it in such a way that it doesn't block my NAS access from windows Explorer. Anybody give me a hint?