My wife and I got matching HP tablet PCs a year ago. (The HP Pavilion tx1420us, in case you were curious.) They sure seemed like a good deal at the time, at half the price of most other tablets. At first, I thought the only reason for the price difference was the screen — these Pavilions used a "passive" touch screen instead of an "active", so they didn't track the stylus; you had to physically tap the screen for anything to register. Unfortunately, it seems the cheaper cost has more to do with the quality of the components.
Apparently, there are compatibility issues with the components used such that, after some time, the computer will simply refuse to detect the existence of the Broadcom wireless card. Trying to find it in the device manager, it's completely gone. My wife's was the first to go, and fortunately it happened quickly enough that it was covered by warranty. Mine held on quite a while longer, until just after the warranty expired.
Since I dual-boot between Windows Vista and the Windows 7 beta, I can pretty definitively confirm it is not a software issue — the wireless card disappeared from both OSes at the same time.
A quick trip through the HP support forums revealed that this problem is far from uncommon, with this and similar product lines, and HP is somewhat less than forthcoming with support, especially after the warranty period.
I did find a support bulletin that seemed to address this problem and offer extended support, but of course it did not include my exact model. They say there is a BIOS update that will help protect against it if you don't have the problem yet. The speculation in the forums is, this will only postpone the problem until it is out of warranty, not fix it. I take that with a large grain of salt, but my own experience does make me suspicious. I tend to keep my hardware more up-to-date with drivers and patches (except for the video driver, which for some reason seems to make things worse on this machine when I try to update). So, my laptop is already running the most current BIOS. My wife's was not. Her wireless NIC failed in-warranty, mine waited until it was out of warranty. It's certainly a suspicious coincidence.
I did give HP support a chance. Two identical notebooks, purchased at exactly the same time. One's wireless card failed after six months, one at 13. The one that failed at 6 months was repaired under warranty, and the one that failed at 13, they want $99 to repair it.
"No, I'm not going to pay to repair it," I told the US customer service rep with the thick southern Asian accent. In fact, this will be the last purchase I make from HP.
Incidentally, this post was made on a 5-year-old IBM ThinkPad T40p that was at one point dropped on a hard tile floor. Had to replace the battery after that, but it still runs great. :P