Re: DESPERATELY need help with LAN streaming
Thanks for the quote BK, but in this instance I'd suspect it's a composite problem. i.e:
a) the usable wifi bandwidth is on the border of managing to stream 720p video
b) the windows 7 PC is able to upload fast enough (if it's managing to get to 30sec-1min before lag)
c) the windows 8 laptop is able to download fast enough but not able to fill a buffer enough to compensate for the drops/retransmissions via wifi
If you plug the two devices in using gigabit ethernet cable directly (or gigabit switch/router) and it works with no lag, then wifi is definitely the problem. Note: use a gigabit connection here to be sure as 100Mb is probably similar to your wireless (assuming N) and might not to have the capacity to smoothly stream 720p. However, given it's stability compared to wifi you'll likely be ok if you don't have gigabit available.
I'm assuming you're not using wireless A, B or G since that has nowhere near enough bandwidth to stream video - which leaves you with N or AC. Both of these should be able to handle that stream (150Mbps/300Mbps for N and 500+Mbps for AC, theoretical maximums).
If wifi appears to be the problem after that test, then try streaming with both machines adjacent to the access point. If you still have issues then check for channel interference (auto settings usually adjust quite well for this). If you have a lot (5+) of other access points in range then you may not be able to get wireless to work for this particular use-case reliably, and it may depend on time of day.