I have a desktop (Acer Revo 1600) running Windows 7 x64 SP1. It has a mini-PCIe slot, into which I installed an Intel 5100 WiFi card. Windows recognizes the card. It sees all of the nearby networks and correctly reports their signal strengths, radio types (g, n, etc.), and security types (WPA2-PSK, WEP, etc.). But when I try to connect to my network, I get an "unable to connect" message. Digging deeper into the diagnostics report, Windows is reporting that it is failing during the association stage (before the security stage), but the reason code that it provides for the failure is 0 (i.e., unspecified). Now, what makes this problem strange is that I have chased this down just about every alley imaginable... Signal strength? This is literally inches away from the router. Strength is high. Could this card be incompatible with this desktop's hardware? No, because when I booted up using Linux instead of Windows, it connected just fine, and I could access resources on the network. Besides, I was able to scan WiFi networks in Windows--just not connect to them. Could it be a problem with the access point? Being able to connect using Linux would suggest "no", but to make sure, I also tried to connect to an entirely different wireless router (different brand/model). Same problem. Maybe the WiFi stack is messed-up in this Windows install? I happen to have two other non-Intel WiFi cards just sitting around (orphans from hardware upgrades). When I replaced the Intel 5100 with those other cards, I was able to connect just fine. Swapped the Intel card back in, and things die again. Maybe Windows 7 just doesn't like the Intel 5100 or maybe this particular 5100. My laptop also runs Windows 7 x64 and it also has an Intel 5100 WiFi card. Never had a problem before (been using the 5100 on the laptop for a few years now). And just to make sure that it wasn't an issue with this specific 5100 card, I even swapped the desktop's the laptop's 5100 cards. The laptop's tried-and-tested card, when put into the desktop, encountered the exact same problems, and the desktop's card, when put into the laptop, worked perfectly under Windows 7. I also have two other laptops that I manage that use the Intel 5100 under Windows 7 x64, and they never exhibited a problem like this. Drivers? I tried this with both the built-in Intel 5100 drivers that Microsoft bundled/shipped with Windows 7 and with the latest drivers from Intel's website. What about anti-virus? None are present on this system. Something is messed up with the Windows install? As a desperate I-am-out-of-ideas last attempt, I installed a fresh new copy of Windows 7 x64 SP1 on the hard drive's spare partition. Still doesn't work. To summarize, I have 3 components: Acer Revo desktop, Intel 5100 WiFi card, and Windows 7. Any two of those components, when put together, works. Replace the desktop with another machine (e.g., my laptop), and the Intel+W7 combo works. Replace the Intel card with a non-Intel card, and the desktop+W7 WiFi combo works. Replace W7 with Linux, and the desktop+Intel combo works. But all three of them together? It hates me. I just wished that Windows could be more specific about the nature of the failure. Or provide better diagnostics/logging. Right now, the most that I can get (when I view the diagnostic details) is the report of an association failure caused by unspecified reasons. Even when I enable tracing (netsh wlan set tracing mode=yes), the tracing analysis didn't say anything more useful than that a connection failed.

It may be due to a static IP address in place. Are you sure the settings for your Wi-Fi card is configured to Obtain an IP address automatically? This theoretically explains your "But all three of them together? It hates me." issue. Windows 7 + Intel wi-fi have these setting saved in the OS so connection fails. Linux + Intel card does not have these settings saved, hence succeeds. Windows 7 + another card has separate settings for the other card, hence the connection succeeds again. Again, your laptop Windows 7 + Intel Card do not have these settings, so succeed again. Makes sense, right? Please use the Windows 7 desktop with the Intel WiFi card, and post the result of ipconfig /all here. I'll assist you further. Hope it helps! Kunal D Mehta - a Windows Server Enthusiast | My first TechNet Wiki Article

A static IP was not set. Furthermore, the default is to use DHCP, and the card still failed to associate even with a fresh install. (But all that is moot: The setting of a static IP or even the failure to obtain a DHCP address would not result in a failure to associate. In the former case, it would simply connect to the network, but I might not be able to send/receive TCP or UDP packets, and in the latter case, Windows will just default to a private address. The problem is a failure to establish a connection with the access point; this failure is happening before the WPA handshake and long before higher-level elements like TCP/IP come into play.) The failure is almost certainly at a low level, but there aren't any tools (that I know of) that could provide useful diagnostic information at that level.

Ok, try to delete the saved wireless connection in the Network and Sharing Center and recreate it. I suspect this has to be the root cause because there is some setting saved in the Windows PC that is causing this problem. Deleting the connection will delete this misconfigured setting too. Steps on how to delete the connection: http://technet.microsoft.com/en-us/library/gg252588%28WS.10%29.aspx#BKMK_Anchor1 After you're done with the above step, search for the wireless connection using the icon in the system tray (right bottom in taskbar) and join it. Hope it helps! Kunal D Mehta - a Windows Server Enthusiast | My first TechNet Wiki Article

Are you using the wifi utility that came with the card? If so, disable it by running MSConfig, click on the startup tab, scroll down the list until you find the utility and uncheck it. The windows wireless configuration does a better job than the utilities supplied by vendors. Jerry

Ok, try to delete the saved wireless connection in the Network and Sharing Center and recreate it. I suspect this has to be the root cause because there is some setting saved in the Windows PC that is causing this problem. Deleting the connection will delete this misconfigured setting too. There are no saved connections. Plus, the problem existed even after a fresh install of the OS. As I noted, the nature of the problem strongly suggests that it is a low-level problem, and I am unfamiliar with what tools and diagnostics are available (if at all) at this level...

Are you using the wifi utility that came with the card? If so, disable it by running MSConfig, click on the startup tab, scroll down the list until you find the utility and uncheck it. The windows wireless configuration does a better job than the utilities supplied by vendors. Intel, thank goodness, no longer provides its own connection utility for their Windows 7 drivers, so that is not an issue (plus, in all of my initial attempts, I downloaded the driver package from Intel that contained only the driver without any external software; I did download and install the full package later on, but none of their provided software was of any use).

Hi, First, just as a reference, I suggest you take a look at the following thread: Wireless association failed due to an unknown reason. If this does not work, please check the event viewer to check the failure information: 1. On a computer equipped with a 802.11 wireless adapter, click Start, right-click Computer, and then click Manage. 2. In the Computer Management console, click Event Viewer, click Applications and Services, and then click Microsoft. 3. Click Windows, click WLAN-AutoConfig, and then click Operational. You could post the result in forum for further analyzing. Alex ZhaoPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, First, just as a reference, I suggest you take a look at the following thread: Wireless association failed due to an unknown reason. If this does not work, please check the event viewer to check the failure information: 1. On a computer equipped with a 802.11 wireless adapter, click Start, right-click Computer, and then click Manage. 2. In the Computer Management console, click Event Viewer, click Applications and Services, and then click Microsoft. 3. Click Windows, click WLAN-AutoConfig, and then click Operational. You could post the result in forum for further analyzing. Alex Zhao Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks for the tip about the logs. I had been poking around the System logs and didn't find anything there; I didn't realize that there was a separate log for WLAN. Each connection attempt generated 4 log entries: * 8000 (WLAN AutoConfig service started a connection to a wireless network.) * 11000 (Wireless network association started.) * 11002 (Wireless network association failed.) * 8002 (WLAN AutoConfig service failed to connect to a wireless network.) The interesting entry is the 11002, where it says: Network Adapter: Intel(R) WiFi Link 5100 AGN Interface GUID: {98692fb7-ed2e-436b-a30e-2cf2745cb959} Local MAC Address: 00:16:EA:73:1E:1E Network SSID: NETGEAR BSS Type: Infrastructure Failure Reason: The driver disconnected while associating. Dot11 Status Code: 2 This was with the second router (which had been reset to factory defaults, hence the generic SSID, and it had no security/encryption). The log entries are identical with the first router (which used WPA2-PSK/AES). So this would seem to suggest a driver problem, which could explain why it works in Linux (if it is caused by a bug that is present only in the Windows version of the driver). I tried three different versions of the driver: the driver that Microsoft bundled with Windows 7 (version 12.something), version 13.5.0.6 from Intel's website, and version 14.0.0.113 from Intel's website. All three driver versions produced the exact same results. The PNP ID of this particular 5100 variant is PCI\VEN_8086&DEV_4232&SUBSYS_12018086. Do you have a way to get in touch with Intel? (But in theory, the WiFi driver should be agnostic with respect to the rest of the system; it should not directly interact with the mobo chipset, for example. I've never had problems with the 5100 card, Windows 7, and ANY version of the Intel driver on other systems, so clearly the driver works in most cases. So is it really a problem with the driver, or maybe a problem with another part of the WiFi stack that just happens to look like a problem with the driver?)

Hi, This could be related to the driver. But sometimes, this incompatible issue could be related to the router as well, have you tried to upgrade the firmware of router to check the result? Alex ZhaoPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

This could be related to the driver. But sometimes, this incompatible issue could be related to the router as well, have you tried to upgrade the firmware of router to check the result? Both routers were using the latest firmware. The likelihood of this being a router-side problem is extremely small, since two different routers (sporting two different WiFi chipsets) were tested, since there was no problem when Linux was in use and no problem when this specific WiFi card was moved to another Windows machine.

Windows 7 connects the best using WPA2\AES security. If you need to have WEP for some reason you will have these issues. Configure the router for WPA2\AES, set a password and disable WEP in the router if that option is available. Drivers are the other problem, but Intel provides those and it is best to use the Windows connection control unless you have Cisco security and AP's. Here; http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Wireless+Networking&ProductLine=Intel%c2%ae+WiFi+Products&ProductProduct=Intel%c2%ae+WiFi+Link+5300+and+Intel%c2%ae+WiFi+Link+5100+products&ProdId=3062&LineId=1784&FamilyId=1783 The association failure is typically network adapter drivers.

I have the same problem, 65536. Before anyone weighs in with the usual suspects, I have done all the things mentioned above and a MS hotfix on the brodcast flag setting thing. Also I have two computers and an ipod on the network. Only this one fails to associate. This one has the Intel 5100 wifi card. Evidntly my Linksys wr45 router is still OK. This pc worked fine until it had a repair ( motherboard thing unspecified) when it seems the wifi card was changed out. All local ap s are recognised and identified along with encryption types. Fails to associate unknown reason The event viewer does not really add anything to the story. It is not really detailed as to blow by blow handshake procedure. I now have no ideas left either.

@Interdog What is a wr45 router? I don't believe it is a linksys product. Which market do they sell that product?

Hello, My problem was very similar: - could see the network, - linux could connect, - could connect to unsecured computer to computer connection, - failed 'association test' Here's what I did (I think #2 is the solution, but giving the other for the record): (1) changed the wifi security to WEP instead of WPA; (2) disabled 802.1x certificate authentication ( to do so go to the Authentication tab of the Properties of the desired network connection); this has solved the problem on another laptop as well. [system: Toshiba Satellite A75-S226 / P4 3Ghz / Windows XP sp3 / Atheros wifi ]