Dunno, I have no issues streaming on my wifi network.
In my old townhouse I had issues streaming fairly high bit rate 720p because I was being crushed by my neighbors wifi networks. However, it was fine up through about 4Mbps, higher and I'd have some issues. I could get faster wifi speeds than that, but streaming didn't work so well.
In my current house with no nearby neighbors I can easily stream 3 medium bit rate (around 12Mbps) 1080p streams over wifi without any stuttering or issues, no probs. I also get around 20MB/sec of throughput on my wifi network on just 2.4GHz 40Mhz 2:2 router, so no suprises that I can stream that fine.
To the OP, for windows, are you using the built in DLNA streaming service? If so DO NOT USE IT, IT SUCKS! I have had so many issues back in the day. Reverting to just streaming through SMB/CIFS worked just dandy, but the built in DLNA server would stumble all over itself trying a couple of different clients. I never figured out what was wrong with it and just gave up. I didn't need DLNA anyway with what I was using, but it was the "better" choice for a number of reasons at the time.