Hi, my computer crashed a couple of days ago because of low battery. When I went to reboot, there was no internet signal or signal icon on the network manager. I have a wusb54gc linksys wifi adapter. It was working perfectly for months, since I installed ubuntu. When I type iwconfig I only get eth0 and lo, no wlan. A similar incident happened to me when my wlan interface changed from wlan1 or something similar to wlan2. My questions are how do I know if my adapter is installed (should work staight out of the box) and working properly? Also, how do I get wlan to show up?

ps: I even reinstalled ubuntu and I still get no wlan. Could this be a hardware issue?

Obligatory question: Are you sure the wireless is switched on? It's not disabled in the BIOS or PXE? There is no hardware switch?

What it is the result of "sudo ifconfig wlan0 up" (no quotes)?