After a brief descent into the usual circles of forum hell, where self-styled hacker doodz spread misinformation and the unfortunate ESL guys patiently try to make sense of it all: here's the short list of things to check.
Update Dec 2: I upgraded Vista to XP, but the problem persists. XP gives a few more things to try:
- used the Dell utility for wireless, and disabled the Windows WZC service
- disabled the Dell utility, and used the Windows WZC configuration for wireless
Also tried a static IP address, which improved the time taken for the initial connection, but it failed in the same way.
Dell 1390 WLAN mini-card, Broadcom 44/10x100 integrated controller. I'm beginning to think the problem is in the 1390 card, since that's the only thing that is different between this PC and the others that work.
The PC works fine at the library with an unsecured network. I tried turning off WPA-PSK at home, and now that works fine too. However I'm not prepared to run without security.
Finally worked around the problem by disabling the 1390 Wlan card, and installing a USB wireless adapter. It's slightly slower, but at least it doesn't crash the entire network on a regular basis. It was a hardware problem, not Vista's fault at all. That hardly ever happens..
Update Aug 29: well, it seems the behavior is by design in Vista. It checks automatically every minute or two to see if there's a better wireless connection. That check will cause a lag in the wireless traffic, and in some cases a complete disconnection. Microsoft believes this to be acceptable behaviour. There are some little programs floating around that may work, try WLAN Optimizer or Vista Anti Lag, but neither worked for me. The only workaround is to buy a wireless bridge, aka wireless gaming adapter, and connect it to the laptop Ethernet port. Then disable the WLAN Autoconfig service in Vista.
Or, simply upgrade to Ubuntu Linux. First get the Live CD, which allows Ubuntu to run from the CD, without needing to install. This is a way to make sure the hardware is supported under Ubuntu. If that runs OK, test the wireless connection under Linux with this step-by-step. All being well, make a dual-boot system with Windows and Ubuntu. Follow the instructions here. Then, boot into Windows Vista when you don't have enough pain and suffering in your life: otherwise use Ubuntu.
Here's the list of other things to check in Vista, just in case something helps.
Change power options.. Start, search for Power Options, then proceed to set it to high performance for everything.
Try channel 11 instead of the default 6. This is set on the router configuration, and should be picked up automatically by the clients.
Both channels 1 and 11 do not overlap with the default channel 6; use one of these three channels for best results.
Turn off the 802.11 authentication.
1. Click Start, and then click Control Panel.
2.Click Network and Internet, click Network and Sharing Center, and then click Manage network connections.
3.Right-click the network that you want to disable 802.1X authentication for, and then click Properties.
4.Click the Security tab, and then, in the Security Type list, click No authentication (Open). Click OK.
Turn off network speed auto-detection:
Select Network Settings, either from your Start menu or from within Control Panel.
Right click on the connection that corresponds to your network card, and select Properties.
In the dialog that results, click on the Configure... button immediately below the "Connect using..." item that shows your network card.
In the dialog that results, click on the Advanced tab.
This is where things vary based on your network card. In the left-hand list will be a series of properties that can be adjusted. Look for a setting similar to "Speed", or "Link", or perhaps "Media Type". Click on that, and the right-hand "Value" dropdown list will probably have something similar to "Auto". If you click on that drop-down list and options include entries that look like "10mbs", "100mbs", and so on, you've found the right item. Change the setting from auto by clicking on the specific speed you've determined you want the network card to run at, and press OK (If the setting also includes a full/half duplex selection, full is normally correct.)
Update the drivers etcetera.
1. Verify that you are using the latest version of the wireless network adapter driver that is available from Microsoft or the wireless network adapter vendor. To obtain the version of the wireless network adapter driver that is installed, right-click the wireless connection in the Network Connections folder. On the General tab, click Configure. From the wireless network adapter properties dialog box, click the Driver tab. The version of the wireless network adapter driver is displayed next to Driver Version. If your wireless client is connected to the Internet, click Update Driver to launch the Hardware Update Wizard and search Windows Update for a newer version of the driver. Alternately, check the wireless network adapter vendor's Web site for a newer version of the driver.
2. Upgrade the router's firmware. Since our Dlink is way out of support, we have the absolute latest 2004 firmware already installed..
From Microsoft's trouble-shooting document, found here:
Wireless Auto Configuration is Enabled and a Third-Party Wireless Configuration Tool is Installed
Windows XP Wireless Auto Configuration provides integrated support for wireless networking and helps automate wireless configuration. Wireless network adapters also provide a wireless network configuration tool. If the wireless network adapter driver supports Wireless Auto Configuration, installation and use of the network adapter vendor's configuration tool is not needed. To test whether your wireless network adapter supports Wireless Auto Configuration, right-click the wireless connection in the Network Connections folder and then click Properties. If there is a Wireless Networks tab, your wireless network adapter supports Wireless Auto Configuration.
Note: there are no third-party configuration tools for Vista. Only the WLAN Autoconfiguration Windows service exists, which is broken as noted above.
If the SSID broadcast is disabled on the preferred wireless network, clever old Windoze might be disconnecting from the network in order to use a different network that is broadcasting its SSID. We do broadcast, so that isn't the case here, but just for completeness..