I am using windows 8.1 and from windows explorer  I could do a 'right click' on an mp3 and select 'Play To' and then select the TX-NR626. Now I don't think I used this feature in February but I certainly did in January 2014 and before. But now the option is no longer available.

So after some googling I found that
1) Apparently there was a windows update in February that had to do with the 'Play to' feature and the support of not certified devices
2) That the registry contains a list of supported devices (in DeviceShims) . I checked the list and indeed the TX-NR626 is not in the list. the TX-NR616 is for example. I don't know if it ever was in the list, I just see that PlayTo is not available any more.

If in explorer I go to 'Network' I see the Onkyo as a MusicPlayer (icon that looks like a portable mp3 player)

Go through the following article:

How to Use Non Certified Play To Devices in Windows 8.1

Hi,

According to your description, I think the problem should caued by computer connection with TX_NR626.

Firstly, please check your device works status in Control Panel\Hardware and Sound\Devices and Printers

It would be better to provide more details about this problem, such as a caputer for "Play to" option no longer available.

Secondly, please try to reinstall Tx-NR626 driver for test.

Hi Roger,

The TX-NR626 does not have a driver, it's just a receiver that 'talks' uPNP.  But you were right,

Going to Devices and Printers showed the ONKYO but 'greyed out'. So when I did 'add device' it found the ONKYO and everything started working. I just had to remove the 'greyed out' device. What I think happended is that my ONKYO changed ip address (It becomes the IP via DHCP). The only thing I don't understand is that I had to do the 'Add Device' . I am certain I never did that before for the ONKYO (and I also see my SONY BRAVIA TV, and I never added that one either).

Thanks for the help.

The "greyed out" status means this device's current status is Offline. This situation can caused by dependent service stopped or system port occpied by other application. Generally speaking, this can be resolved by readded the device.

Glad to see your problem resolved.