First, I really think you need to replace the Trendnet switch. It doesn't have a large enough buffer. The one I linked in one of my earlier posts is the one I use in both locations, and it works perfectly... even though I have two of them daisy-chained together. It's not very expensive either.
here's the link to the switch I recommend.
Secondly, I can't find any information about your Verizon router as to its buffer size or anything else for that matter. It may or may not be a good choice to use as a pass-thru for your Media Center Extender traffic. I can't really say... but I found a number of posts on other sites where people were complaining about this router's capabilities.
Third, you never mentioned this other router that you are using to plug in your HTPC, HDHR Prime, and printer. That one could be suspect too... especially if you're passing the connection through the router (using the WAN port) instead of just passing the data through the router's internal switch (using only the LAN ports). This is really a big one. You DO NOT want to use the WAN port in this extra router to up-link to the TrendNet switch. You are using that extra router as nothing but a switch, right?
At a minimum, I strongly recommend replacing the Trendnet switch and this other router with the switch I've recommended a couple of times in this thread. Two of them would cost you about $70.00 from NewEgg.
However, it would be best if you can re-wire. It would be far better if all your Ethernet cables run to a central location near your Verizon router, eliminate the MoCa adapter, and connect your HTPC and all your extenders to the same switch... preferably the one I recommended above. Is there a reason why you can't re-wire?
If it's
absolutely impossible to re-wire (or at least eliminate the MoCa adapter), then your best bet is to move the Verizon router to the location where the HTPC is. Then, you could connect your HTPC ,HDHR Prime, and printer to the router directly (this eliminates one "hop" for the MoCa adapter to the living room)... and then up-link from the router to a new switch (using the one I recommend... in the location where the TrendNet switch is located now). You would connect all your other stuff to the new switch.
Before you do anything though, I recommend this test: Go out and buy a "Crossover Cat5e Cable" (
see this link for examples). You can either buy one long enough to connect all the way from your HTPC to one of your XBoxes, or you can buy a short (cheap) cable... and move the PC or the XBox (and the TV) so they are close enough to one another. Then, you can connect the XBox directly to the PC using the crossover cable to test to see if you still have a problem. You won't be able to connect your HDHR Prime... you'll need to perform the test with some shows that you've previously recorded. This creates what is known as a "peer-to-peer network". If this test works, it eliminates your PC as the problem (except, possibly the network card and its settings).
So, do the test I mention above. If it works fine, then rewire and buy one of the switches I recommended. If you can't rewire, buy two switches. Here are three possible scenarios that you could try... and they should work better than what you are doing now:
OPTION 1: Re-wire(Leave Verizon Router where it is)
HTPC -> ASUS_GX-D1081_switch_A(Port1)
HDHRPrime -> ASUS_GX-D1081_switch_A(Port2)
Printer -> ASUS_GX-D1081_switch_A(Port4)
ASUS_GX-D1081_switch_A(Port3) -> ASUS_GX-D1081_switch_B(Port1)
ASUS_GX-D1081_switch_B(Port2) -> VerizonRouter(Port1)
ASUS_GX-D1081_switch_B(Port3) -> LivingRoomXBox
ASUS_GX-D1081_switch_B(port4) -> wired -> Bedroom -> 2nd_XBox
ASUS_GX-D1081_switch_B(port5) -> wired -> Basement -> 3rd_XBox
ASUS_GX-D1081_switch_B(port6) -> wired -> Another Room
ASUS_GX-D1081_switch_B(port7) -> wired -> Bedroom -> 4th_XBox or Ceton Echo (coming soon)
OPTION 2: No_rewiring(Leave Verizon Router where it is)
HTPC -> ASUS_GX-D1081_switch_A(Port1)
HDHRPrime -> ASUS_GX-D1081_switch_A(Port2)
Printer -> ASUS_GX-D1081_switch_A(Port4)
ASUS_GX-D1081_switch_A(Port3) -> ASUS_GX-D1081_switch_B(Port1)
ASUS_GX-D1081_switch_B(Port2) -> VerizonRouter(Port1)
VerizonRouter(MoCa) -> LivingRoomXBox(MoCa)
ASUS_GX-D1081_switch_B(port4) -> wired -> Bedroom -> 2nd_XBox
ASUS_GX-D1081_switch_B(port5) -> wired -> Basement -> 3rd_XBox
ASUS_GX-D1081_switch_B(port6) -> wired -> Another Room
ASUS_GX-D1081_switch_B(port7) -> wired -> Bedroom -> 4th_XBox or Ceton Echo (coming soon)
OPTION 3: No_Rewiring(new switches, move Verizon Router)
HTPC -> VerizonRouter(Port1)
HDHRPrime -> VerizonRouter(Port2)
Printer -> Verizon Router(Port4)
LIvingRoom(MoCa) -> VerizonRouter(MoCa)
VerizonRouter(Port3) -> ASUS_GX-D1081_switch(Port1)
ASUS_GX-D1081_switch(port 2) -> wired -> Bedroom -> 2nd_XBox
ASUS_GX-D1081_switch(port 3) -> wired -> Basement -> 3rd_XBox
ASUS_GX-D1081_switch(port 4) -> wired -> Another Room
ASUS_GX-D1081_switch(port 5) -> wired -> Bedroom -> 4th_XBox or Ceton Echo (coming soon)
I'm sure you can see that you could come up with lots of options. The main objective is to minimize the number of "hops" through switches and routers between your HTPC and the extenders. Also, you need to use better switches. Eliminating MoCA (or at least wiring it so that there are fewer "hops") is a good idea.
There are lots of things you can try. I will say that the network interface you bought is about as cheap as you can go. Mine is built on the motherboard in the HTPC... and it's a RealTek... which some people say they have problems with. However, I think your first and most effective change is to eliminate as many "hops" as possible... and replace the TrendNet switch and that other router that you are effectively using as a switch with the switch(es) I recommended. Your problem is most likely network latency... and you may not see this when you just copy a file from one computer to another.