I've got a problem with my son's Inspiron 530 running Vista. This came with the Dell/Broadcom 802.11g wireless adaptor, and a Dell supplied D Link DI-524 802.11g router. The router is connected to a 4Mb/s cable modem. Initially this worked well, but now the Inspiron still gets a network connection, and although Windows describes the signal strength as "very good", it only achieves about 14,400 modem speed (remember them?). The Dell Support center reports that it can't even detect a network connection, although if I wait long enough browsers will eventually display content. The network is set up using WEP encryption.
The router is also used with a wired connection to my Dimension 9200 (using it at this moment) and that operates smoothly and fast, so there's no cable modem issues. The two household laptops both connect quickly and at full wireless speed, so I know the wireless router can work OK. As my son's machine is only about eight feet from the router, and the laptops work fine from longer distances, I guess that there aren't any interference problems, and the signal strength is good throughout the house.
The Inspiron is running anti-virus software, I've done a full scan for malware and found nothing (in any event my son's only 8, and not into downloading rubbish from the internet, added to which he only has "user" access). A look at Task Manager shows very low CPU usage when running a browser (as you'd expect) but very low utilisation of the wireless connection - around about 1%.
Rebooting the Inspiron hasn't helped, neither has full powerdown of the routers and modems. I've tried upgrading the router firmware, with no evident success, and I can't see anything obvious in the Broadcom card settings.
Is the connection also slow if you connect this computer to the router by wired etherent? If so, then we can narrow the problem to the wireless adapter rather than a software problem or general networking problem.
Connected it hard wired, and the connection runs at full cable modem speed, so that pins it down to the wireless card and/or settings.
Incidentally, I tried one of the laptops from the same physical location as the problem machine, and tried loading the same page over wireless. The laptop worked fine, the wireless desktop still had the same problem. This seems to me to rule out interference from wireless phones, keyboards, and other location specific types of problem.
A solution! Reloaded the drivers from the Dell web site, and it works again. No obvious reason why the pre-installed driver should stop working, other than perhaps some auto update that fouled up the system, but I've not got anything to prove that.
Incidentally, the system identifies the card as a Broadcom device, Dell refer to the drivers I've downloaded and am now using as for an Asus product, and the card when I bought it was referred to as a Dell OEM product.
Thanks to all who passed by and read the thread.