I have a WD MyCloud 4TB NAS. I was able to transfer about 116GB (31 mkv files) with no problems. Properties under Windows shows it's a Windows NT 4.9 Server. I use a Netgear 7550 Router Modem my ISP (Frontier) provided. I can no longer transfer any large files (>100MB) to the device without it "crashing". The error message claims there is no network connection yet I can clearly see the device and all the files & folders on it. I have to kill the transfer, delete all traces of the file from the WD, and sometime reboot. I doesn't matter if I transfer wirelessly or directly from the Seagate GoFlex Home (3TB) using the network ports on the modem. WD sent me a new unit and exhibited the same problem. WD Support did everything short of coming out to my place to try to diagnose and fix the problem (Now there's a story from Grimm's Fairy Tales). I have no problems with the GoFlex. I've switched ports on the modem and the problem continues. Could the 7550 be the problem. I had ZERO problems using a fiberoptic modem with Cincinnati Bell with the NAS drives, the HP wireless printer (which also likes to mess up since we went on the 7550)? Any suggestions would be greatly appreciated. And, no, there is no other game in town. It's either Frontier DSL or Frontier dial-up.