See this (six month old) message by Chris (CEO of ThinkPenguin):
The problem with HP is they are on the 'bad list' of companies in that they use digital restrictions to prevent the user from replacing it with another card. This is done because there is a lucrative market for after-warranty part sales. By restricting the cards which work in this slot it forces customers back to HP for a replacement part. There have been claims by HP/and or other companies that this is done to comply with FCC rules. However the free software community made a huge fuss about it (amongst others) and the FCC responded with a public statement saying this was false. There are no such regulations that would prevent the company from letting users install third party cards. After this they made further claims about it not being the FCC but other countries. The problem with this is that the original claims were very specific and other companies would be in the same situation. However the list of companies implementing these restrictions is fairly short: HP, Dell, *Toshiba*, IBM/Lenovo, and Apple (via a proprietary component), and possibly Sony. Asus, Acer, and most others have no such restrictions on there systems. These are not small companies whom only target the US market or any other small market and would also be in the same position as HP were this true.
While you can't replace the wifi card in this system you could use an external USB wireless adapter to work around the problem. It may not be ideal although if you already own the system (and have for some time, ie can't return it) then it is you next best option.
