I've recently built the NUC (5420WYKH) and used all components that are on the tested list. I installed Win 8 64-bit and upgraded to Win 8.1 64 bit. I am having problems with the wireless card. The connection drops, always the same way, first it shows limited connection, then the machine can't find any networks. I have installed the latest driver from Intel (also tried the Windows built in driver), and control panel shows 'this device is working properly' even when it isn't working at all! Sometimes it shows no driver installed once the fault condition occurs. I have unchecked the boxes to allow the pc to switch off the card to save power (and in Bluetooth too) and disabled Wireless N.
Any suggestions? Is it likely to be a faulty card? The card is mounted (with its fixing screw) under the mSATA drive.
Thanks.