I’ve had some awkward problems with the wireless connection at work – the box is a WinXP Pro SP2 – and they didn’t seem to fit in with the normal heap of wireless issues. What happened was that it took an awful long time to log in on the domain, and starting up the OS was immensely slow due to the lack of a network connection. Repairing simply didn’t work, since the connection was already excellent according to Windoze, but I couldn’t ping the local servers, printers or anything else.
This morning, after a long problem-free period, I had the same problem again. Then I remembered that I had updated VMware to the latest version, and consequently activated the VMware network adapters. I disabled them, renewed the dhcp lease, rebooted et voilá!
This is an Inspiron 6k with the Intel(R) PRO/Wireless 2915ABG card.
In other cases, especially with slower (802.11b) network cards, I’ve found that Windoze Automatic Updates seem to block off necessary traffic (like clearing the ARP cache, dhcp request aso) while trying to download updates. This causes an evil circle of AU trying to download updates while keeping the computer off the wireless network. Turning AU off and ipconfig /renew seems to work. In those cases I’ve just told the client how to download manually through the Automatic Updates website instead (which is what I myself do anyway).