So, to "fix" the problem with my HP tx1420us laptop that sucks in that it no longer recognizes the fact that it has a wireless network card installed, I went out and bought a USB Wi-Fi adapter. I found some online for about $20, so when I went to Best Buy, that was my target price. Unfortunately, they didn't carry any that weren't under $50. Wal-Mart, however, had a Belkin 802.11g for $30, and that was close enough for me. (The one installed in my laptop is 802.11n, but my access point is only a "g" anyway.)
I first installed it in my Windows 7 beta partition, and the installation went very smoothly. Unfortunately, though, I still had to re-configure my wireless settings — apparently, Windows 7 binds wireless configurations to the adapter, so my home WAP's configuration bound to my Broadcom card was not accessible. Not a big deal, though.
Then, I figured I'd better install the software on my Vista partition as well, before I put the CD away. One of the things they tell you to do is to install the software from the CD first, and then plug in the USB device. So I pulled the adapter out, rebooted into Vista, installed the software, and plugged in the adapter again when it prompted me. Again, I had to reconfigure my wireless settings — the binding of settings to adapter must've been a Vista thing that Windows 7 inherited.
That finished, I rebooted into Windows 7. The network adapter was detected, but it did not automatically connect to my WAP. When I pulled it up, I saw that "Belkin USB Wireless Adapter #2" did not have any wireless configurations assigned to it. Apparently, what happened was, when I was installing it in Vista and re-attached the adapter into one of the two side-by-side USB ports on the back of my laptop, I plugged it into the one other than the one I had first used for Windows 7. When Win7 booted, it found the adapter not in port #1, but in port #2, and therefore it assumed it was an entirely different adapter. (Funny, these things are supposed to have unique hardware addresses; it couldn't detect it was the exact same adapter, just moved?)
So now, when I reboot into the other environment, I have to remember to switch the USB ports for my wireless stick. Or just define the same profile for "Adapter #2". Either way, it just seems obnoxious.