Alienware M14X R2 Wifi Constant Wifi Disconnects

Hi I purchased my Alienware M14X R2 about 7 months ago.  For the first 6 months the wifi worked flawlessly.  I used the laptop to stream media from my HTPC and desktop without any problems.  All of a sudden 1 month ago it started disconnecting at intervals of 30 mins to an hour.  Sometimes more.  I had a TPLink USB Wifi dongle handy and plugged that in to the laptop.  That worked fine, no disconnects.  So I called tech support and sent it out for a repair.  The bigfoot killer 1202 card was supposedly replaced.  I got the laptop back, though I had several scratches and dents in the laptop that wasn't there before I sent the laptop for repair, I would have been glad if it started working like it did before.  It lasted 2 days and the signal started dropping again and again.  

Nothing has changed in any of my hardware.  The laptop sits 3 feet away from the router.  So I called tech support again and they decided to send me an Intel Centrino Ultimate-N6300 to install on my own since I complained about the previous damage caused by the technicians.  I watched a youtube video on how to remove the wifi card.  Nothing difficult.  So I installed the centrino card and sent the bigfoot killer one back, not really sure how much time I had to send equipment back.  This one was even worst, when it lost connection my entire laptop would freeze, requiring a manual reboot of holding the power button down.  I thought maybe it was a driver conflict with the previous card, so I formatted the HDD and did a fresh install of windows, not 30 minutes into installing the latest intel drivers (15.8.0) for the 6300 the wifi connection dropped and the laptop froze again.  I uninstalled the latest drivers and went with an older one (15.6.1), same issue.  Then I decided to install a dell N6300 driver, that was even worst, BSOD's and wouldn't even boot unless in safe mode.  This forced me to uninstall the drivers and reinstall the latest ones again (15.8.0).

I then decided to buy a new router, to eliminate the possibility of that being as issue, even though the router I had was only 5 months old, and my $15 TP Link USB wifi dongle works flawlessly with the laptop.  I had an Asus RT-N16.  I decided to buy an Asus RT-N66U.  I got the new router a few days ago and again as I suspected it would, it started dropping signal intermittently again.  I stream the same files to other devices without any issue.  The USB wifi dongle works flawlessly without dropped signal.   My tablet streams wirelessly without problems.

At this point isn't it likely something else is broken other than the wifi card.  I'm going to list some things I've already done below just to clarify the situation.  Please someone help me, are there any moderators who can provide some insight on this?

-called tech support, did uninstall and reinstall of driver via remote access, that didn't work and I sent it in for repair

-called tech support, the tech told me to uninstall drivers use a driver cleaner and reinstall, even though i was reluctant to believe him, he swore up and down it was a known issue and the bigfoot killer driver cleaner would definitely fix it.  He remotely connected did his thing, 3 hours later signal started dropping again and again.

-called tech support again for the 3rd time, explained situation, they decided to send me a different wifi card.  exacerbated issue, not only does it disconnect it also freezes the laptop upon disconnect.

-No hardware changes have been made to my network and setup, except the new router purchase to eliminate possibility of router being the issue.

-Laptop has always been in the same spot as from day 1.

-Laptop worked flawlessly for 6 months then started losing signal.

-Only the laptop loses the connection.  I have 3 computers in total and they are turned on at the same time.

-I have disabled the power management option to turn wifi off for power save.

Alienware M14X R2

Windows 7 Ultimate 64

Intel i7-3840QM

Crucial M4 mSATA 256GB SSD

Killer Wireless-N 1202 --> (now) Intel Centrino Ultimate-N6300