I had the same problem using Windows 8.1 until I made some network setting changes in Windows.
Here's what I did to fix my problem. Under control panel=>network settings=>Advance sharing settings; Check the follow sections.
Guest or Public “Turn on network discovery”
All networks/Password protection sharing: “Turn off password protected sharing”
S2(03/2006), S3(10/2006) (OTA), TiVo Hd(04/2010), Premiere(05/2012) (OTA), Roamio Basic (11/2013)(Comcast Cable).