DW1520 Wireless-N Adapter Connecting Erratically

Hi all:

My wireless network adaptor (DW 1520) seems to be working erratically, or not at all.  Problem description:  When I attempt to connect to a wireless network after a few seconds of "Getting information from [network]" Windows 7 says “Windows was unable to connect to [network name]” after requesting that I enter the security key (when applicable, have tried a totally open unprotected network).  Note that when security settings are enabled on the network, the adapter is evidently not getting far enough to check the password.  (If I misenter a correctly formatted password, it yields the same error message instead of an "incorrect password" message).  On a few rare occasions, provided the wireless network is set up manually and has “connect automatically” enabled, the laptop will connect to the wireless network, and even successfully exchange some data (e.g. I can pull up Google), before the laptop drops the network again.  I would also note that the wireless adapter seems to report the strength of nearby networks (<5 feet) erratically, sometimes full bars (as expected) and sometimes not appearing on the list, or as a “poor” or “fair” signal.

This is probably a problem with the laptop (Alienware M11x) not the router:  I have tested with two separate routers (Belkin G Wireless and Linksys WRT150N) on all security protocols (including default open unprotected) and confirmed that other devices are able to connect via the wireless networks from these routers.  The laptop is about one year old, and was last reliably connected via wireless two months ago (9/5/11).  The laptop has no problem connecting via the Ethernet port, through either of the routers, or directly to the cable modem.

It currently appears that this is most likely not a hardware problem:  The DW WLAN Card Utility passed all “hardware diagnostics” successfully.  On the rare occasions where the laptop was connected to a wireless network and I attempted to run the “connection diagnostics” the tests would pass up to “Gateway IP ping” and fail “Internet IP ping” and skip the remaining tests.  I also spoke with Dell Technical Support, who is normally a great team, but after conducting some additional tests, checking for updated drivers and BIOS, they concluded that this is not “their” problem and that the problem probably lies with Windows 7, which they will not support under my CompleteCare service contract.

At this point I’m tired and frustrated, and considering a complete factory reset – can anyone suggest an alternative that wouldn’t require all the pain and suffering involved in a total rebuild of my system?  I am also happy to respond to any additional information requests if someone wants to help me troubleshoot in detail.  I'm being to seriously contemplate "accidentally" breaking my machine irreparably just to get a new laptop.

Solutions Tried and Failed (individually, not in tandem or sequence):

• Running the Windows 7 Troubleshooter (including resetting network adaptors, in tandem with routers and separately)
• Disabling and re-enabling the wireless adapter, with and without computer restart in between.
• Uninstalling and reinstalling the network adapter drivers
• Windows System Restore back to last period when WiFi was working reliably
• Bios Update
• Safe Mode with Networking boot
• Turning off "Allow the computer to turn off this device to save energy"
• Changing antenna diversity to “Aux” and “Main” instead of “Auto”
• Setting router to use G-band only (instead of both B- and G-band)
• Disabling IP Helper from service.msc
• Disabling IPv6 from Network Adapter configuration 

System Information:

Host Name:                 JHWANG-PC
OS Name:                   Microsoft Windows 7 Home Premium
OS Version:                6.1.7601 Service Pack 1 Build 7601
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Workstation
OS Build Type:             Multiprocessor Free
Registered Owner:          JHwang
Registered Organization:   Microsoft
Product ID:                [Redacted per instructions]
Original Install Date:     10/12/2010, 1:35:51 AM
System Boot Time:          11/1/2011, 10:59:22 PM
System Manufacturer:       Alienware
System Model:              M11x R2
System Type:               x64-based PC
Processor(s):              1 Processor(s) Installed.
                           [01]: Intel64 Family 6 Model 37 Stepping 5 GenuineIntel ~1200 Mhz
BIOS Version:              Alienware A04, 11/23/2010
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume2
System Locale:             en-us;English (United States)
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC+07:00) Bangkok, Hanoi, Jakarta
Total Physical Memory:     3,894 MB
Available Physical Memory: 1,989 MB
Virtual Memory: Max Size:  7,786 MB
Virtual Memory: Available: 4,733 MB
Virtual Memory: In Use:    3,053 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    WORKGROUP
Logon Server:              \\JHWANG-PC
Hotfix(s):                 71 Hotfix(s) Installed.
                           [01]: 982861
                           [02]: KB971033
                           [03]: KB2305420
                           [04]: KB2393802
                           [05]: KB2425227
                           [06]: KB2446710
                           [07]: KB2476490
                           [08]: KB2478662
                           [09]: KB2479628
                           [10]: KB2479943
                           [11]: KB2484033
                           [12]: KB2485376
                           [13]: KB2487426
                           [14]: KB2488113
                           [15]: KB2491683
                           [16]: KB2492386
                           [17]: KB2503658
                           [18]: KB2503665
                           [19]: KB2505438
                           [20]: KB2506014
                           [21]: KB2506212
                           [22]: KB2506223
                           [23]: KB2506928
                           [24]: KB2507618
                           [25]: KB2507938
                           [26]: KB2508272
                           [27]: KB2508429
                           [28]: KB2509553
                           [29]: KB2511250
                           [30]: KB2511455
                           [31]: KB2515325
                           [32]: KB2518869
                           [33]: KB2522422
                           [34]: KB2524375
                           [35]: KB2525694
                           [36]: KB2529073
                           [37]: KB2530548
                           [38]: KB2532531
                           [39]: KB2533552
                           [40]: KB2533623
                           [41]: KB2534366
                           [42]: KB2536275
                           [43]: KB2536276
                           [44]: KB2539635
                           [45]: KB2541014
                           [46]: KB2544893
                           [47]: KB2545698
                           [48]: KB2547666
                           [49]: KB2552343
                           [50]: KB2555917
                           [51]: KB2556532
                           [52]: KB2559049
                           [53]: KB2560656
                           [54]: KB2562937
                           [55]: KB2563227
                           [56]: KB2563894
                           [57]: KB2564958
                           [58]: KB2567053
                           [59]: KB2567680
                           [60]: KB2570791
                           [61]: KB2570947
                           [62]: KB2572077
                           [63]: KB2579686
                           [64]: KB2586448
                           [65]: KB2603229
                           [66]: KB2607712
                           [67]: KB2616676
                           [68]: KB958488
                           [69]: KB976902
                           [70]: KB976932
                           [71]: KB982018
Network Card(s):           3 NIC(s) Installed.
                           [01]: Atheros AR8132 PCI-E Fast Ethernet Controller
                                 Connection Name: Local Area Connection
                                 DHCP Enabled:    Yes
                                 DHCP Server:     192.168.1.1
                                 IP address(es)
                                 [01]: 192.168.1.100
                                 [02]: fe80::29e1:602c:2a5b:a90b
                           [02]: DW1520 Wireless-N WLAN Half-Mini Card
                                 Connection Name: Wireless Network Connection
                                 Status:          Media disconnected
                           [03]: Microsoft Virtual WiFi Miniport Adapter
                                 Connection Name: Wireless Network Connection 2
                                 Status:          Media disconnected

IP Config Details:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\JHwang>ipconfig/all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : JHwang-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : Belkin

Wireless LAN adapter Wireless Network Connection 2:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft Virtual WiFi Miniport Adapter
   Physical Address. . . . . . . . . : C0-CB-38-22-CB-78
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Wireless Network Connection:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : DW1520 Wireless-N WLAN Half-Mini Card
   Physical Address. . . . . . . . . : C0-CB-38-22-CB-78
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : Belkin
   Description . . . . . . . . . . . : Atheros AR8132 PCI-E Fast Ethernet Contro
ller
   Physical Address. . . . . . . . . : 5C-26-0A-0B-FC-39
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::29e1:602c:2a5b:a90b%10(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Tuesday, November 01, 2011 11:02:39 PM
   Lease Expires . . . . . . . . . . : Wednesday, November 02, 2011 11:02:39 PM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DHCPv6 IAID . . . . . . . . . . . : 240920074
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-14-39-52-F4-5C-26-0A-0B-FC-39

   DNS Servers . . . . . . . . . . . : 192.168.2.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{7CC8A7D9-5DC8-4811-A9DD-6542A960B631}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:1c1a:210:89b9:7ff2(Prefe
rred)
   Link-local IPv6 Address . . . . . : fe80::1c1a:210:89b9:7ff2%11(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter isatap.{E591BF72-2750-45D8-B710-CB110ED0FF39}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #4
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter isatap.Belkin:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : Belkin
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes