I have a fairly new satellite c655-s5049 laptop bought from the US.
Recently, the f8 flash card disappears and i am unable to use wireless to connect to internet at all. Sometimes, it would suddenly show up when i start the com but it shows as "communication switch is disabled." Or else, i would not be able to connect to any access points as it shows "no connections are available".
I have tried reinstalling the atheros wireless driver but to no avail. The thing is, i check the device manager and it does not seem to detect the wireless card at all.
Is it a problem with my card or is it something wrong with the driver?
Hard to say at this point whether it is the card or driver. But, the type of intermittent performance you describe, and the fact that it's not appearing in Device Manager, is usually indicative of a device that's failing, or has already failed. But, could still be a driver, or the WiFi card itself may just need to be reseated.
First, the Atheros driver on your Toshiba USA downloads page is quite old. So, let's try this newer version from Toshiba Europe. This is a zip file so you'll have to extract the .exe file to install it.