is this Bandwidth Throttling?

Hey guys, before I go into more specific detail, this is a wireless problem. I have Verizon Fios, my speed is supposed to be 75/50. I have 2 desktops, and 1 laptop all running 7, connected to the same network, along with 2 game consoles, 2 tablets, and 2 smartphones. I am not running any anti-virus on anything. (I dont know if this helps, but all the computers use firefox) and most importantly, until about 2 weeks ago, the speeds we were getting were great, no problems with the connection ever. Ran like gold to be honest. Then my PC lost connection, completely. Called Verizon up, they said everything was fine as far as they could see, no problems with the connections at all. They reset everything and did what they normally do when you call and I still couldnt connect. Then about 2 days later the whole network crashed, called again, they sent out a new router, everything connected fine yet again, except my PC. It connected this time, **when I hover over my network connection, it says I have an excellent connection. There are no known problems with my network card, or anything else in my computer.** so, It connected this time, but when I went to check the speed, it was shockingly low. A whopping 0.68 download over 1.12 upload. I used Hitman Pro, and Little Registry Cleaner, I reinstalled the drivers for the network card. I reformatted my entire computer after hours of frustrating thinking and what if's that never panned out, still no help. A few days ago I was messing around in system settings and all that and I turned off remote connections to my computer, and took a speedtest right after, and it shot up to about 30/40. Stayed like that until morning, then it just kind of alters between around 30/40 and a usual 5/10. I can use normal websites, I cant stream video or download anything, well I can but it just takes a while. I am so far out of ideas and options..I really hope someone has an idea or solution but I also hope no one has to go through this ever, it is horrible.

ok, so its sort of happening to the other devices, but not as excessive. the other devices, they just disconnect and reconnect every now and then but the speeds when connected are fine. as for wired connections, I really dont know why (maybe its the cable?) but it wont recognize that there is a wired connection in. I havent tried to move my computer downstairs (to the router) because my monitor is my television..I mean I could always hook it up to the other tv worst comes to worse..and yes safe mode with networking I can get into, last time I did (about a week ago) the speeds were the same, maybe just a touch faster. Ill load it up now and see what happens.
also, since Ive posted the original question..Ive been doing regular speedtests and its been showing around 40/50 all the time, but say I went to stream something, it just freezes up and wont load, or just loads segments and plays like a skipping record. and I did download and install Xirrus..just not 100% on what to do with it
Thanks so much for responding!

The cable I was using was just I guess standard size.
I called verizon again, with determination and apparently they have two sets of tech support but they still say that there is nothing on their end and it must be something interfering, they told me to run the verizon in home agent, and something did pop up and said there is interference from 2 or 3 sources. I just dont understand if thats the case, if that really is it, why did it happen now..and why isnt it effecting the other computer not even 4 foot away from mine. I am afraid that my knowledge for computers and networking are pretty much useless these days since I havent really kept up on anything since xp was relevant lol
Thank you again so much for your time, I really do appreciate it

**I just noticed that its only registering one wireless network, on xirrus and my computer. which is really weird because I usually pick up about at least 4 others around me. The other computers are picking them up. I dont know if that helps or changes anything but I figured I would mention it just in case..better to be detailed than sorry I suppose lol

As for your speed issue, you would actually need to plug a computer right into the Verizon modem/router and run a speed test. (Make sure you run speed test in safe mode) If speed test is correct directly then it would have something to do with wifi portion.

If speed is correct via hard wire do this:
You may have to look at logs to see how many computers/devices are connected. Remove any unrecognized computer/devices from the router DHCP client list. First thing you would need to do is remove all wireless computer/devices connected to it and connect computer/device at a time and run a speed test to see if your getting the right speed.

Make sure you do the speed test in safe mode, there might be some software that could be slowing your speed.
I use to work for a ISP and if we send out a tech and he's able to get the proper speed directly and wirelessly and it was something on the users end we would charge a call out fee since the problem was the user and not the provider.

I did manage to connect it and the speeds were more than fine, so it is def. wireless issues...I moved my setup a little closer and I the speed is picking up a tiny bit but barely. Maybe like a 10% increase. I am not 100% on the NIC thing, I can guess and put what I could only assume very well maybe help? It is a broadcom WLAN Adapter. and then I got this about it off HP? I have no idea if this helps at all, and if it does not I am so very sorry.


802.11 wireless b/g/n & Bluetooth 3.0 half-length PCI-Express Mini card

• Interface type: PCI-e half-length mini card socket
• Electrical interface:
  
  • WLAN : PCIe 2.0, CEM1.1 compliant with no Vaux support.
  • Bluetooth: Compliant with USB 2.0.
  
  
• Data transfer speeds: up to 300 Mbps
• Transmission standards: 802.11 b/g/n
• Antennas: 2 (internal)
• Operating band: 2.4 GHz single band
• Supported security protocols:
  
  • WPA, WPA2
  • WEP
  
  
• Bluetooth 3.0 spec compliant

I also went into my router settings and deleted all the devices connected and one by one re-added them. deleted anything suspicious permanently as well.