I updated my system a few days ago, now every time I start it up, I have to "F2" to reset the BIOS WIFI to "Enabled"... Where do I look for whatever runs in the background to turn it off again?? The blue LED stays on, but each time it boots up as "Disabled" in the BIOS???? Help!! Dave

Modified menu.lst as recommended elsewhere here... It WOKED!! The steps are..
In terminal.. backup the original..
sudo cp /boot/grub/menu.lst /boot/grub/menu.lst.backup
Then Edit Menu.lst
sudo gedit /boot/grub/menu.lst
Find .. #defoptions=quiet splash and add this.. pciehp.pciehp_force=1 pciehp.pciehp_poll_mode=1
finished edit should look like this...
#defoptions=quiet splash pciehp.pciehp_force=1 pciehp.pciehp_poll_mode=1
Save and exit gedit..
Then type...
sudo update-grub
That's it... next boot, everything worked...!!!

Thanks DJKnut. The solution you gave has worked for me too! Much appreciated.

Regards,
Rab

One thing I have noticed after using this fix when booting, after the grub menu I get the following message flashed up on screen:

Starting up ...
[0.888028] pciehp 0000:00:1c.3:pcie04: Device 0000:01:00.0 already exists at 0000:01:00, cannot hot-add
[0.888091] pciehp 0000:00:1c.3:pcie04: Cannot add device at 0000:01:00

it's just telling you you can't re-add devices that already exist, you can ignore it.

Alternatively, it seems to work adding the two pcihp options to /etc/modules. I get toggled wifi, and no error

Interesting, I upgraded and broke my wifi too. I had no idea how to fix it, and luckily came across this. Although I followed the steps and it didn't seem to help.

But I did think to check the BIOS anyway, and it had been disabled (despite having the blue light still tell me otherwise), I didn't know software can interact with the BIOS. I thought it was safely stored away on it's own little chip somewhere.

Also, would really like to know how you came to lean of the answer, DJ Knut. but thank you anyway for the help

update,

i still have to enable wifi in the bios at every startup, editing menu.lst or /etc/modules has not fixed matters on my lowly 701

I'm having this problem too, and the proposed solution doesn't seem to work on an Eee 900.

Any ideas?

Also, I just pulled up the driver info from lspci, in case the driver is at fault.

The wireless adapter is recognized as
Atheros Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter (rev 01)

and the current driver is "ath5k".

Can you explain this more (I am a noob). I want to give this a shot. The solution in the OP did not solve my problem.

I'm sure he means to open a terminal, type in:

sudo leafpad /etc/modules

and add these two lines to the bottom of the page:

pciehp.pciehp_force
pciehp.pciehp_poll_mode

done.

But I don't fully understand how that is supposed to help. These 'modules' (if they even are modules) weren't enabled before the update.

For the sake of your noobdom, the terminal command is only opening a text editor application to edit the file modules in the /etc/ directory. the text file just tells the kernel what modules to activate at startup (like mac os 9 extensions).

And I need a big cup of tea, being severely hung over.

Actually, and this appears to be really, really important, the pciehp options have to be added at the top of the file (not including comments) because there is a dependency issue with one of the later modules (i2c or netbook or something, I forget). Doing that gave the same effect for me as adding the lines to grub. A reboot was required in both cases.

I think this works roughly the same way as adding them to grub; in grub, they get appended as drivers (modules) the kernel must load. In modules, they are essentially after-kernel drivers. The key is that the drivers are apparently already compiled into the kernel, but there's some problem that requires them being reinitialized (no clue what problem). This, incidentally, is what's causing the errors on suspend/resume when it's added as a grub option; the kernel is telling you it already loaded those modules.