Computer will not boot after installing new hardware. I was trying to install a airlink wireless cardbus adapter to my compaq evo 1020 laptop running xp. I followed the instructions. First I installed the adapter into the slot then turn on computer. I did that and it locked up when windows was installing the programs on the desktop. I did a hard shut down. and when I reatarted the screen would not even light up. I reatarted several times with different combanations of restarts with the wireless card in the slot and with out. after several attempts (with the wireless card in the slot) it started up windows again but locked up in the same manner. I cant get the monitor to even light up again. Need help! Thank you

Remove the card, return it to the shop. You obviously didn't get the chance to install any? drivers...
Meanwhile try Last Known Good Config. If that won't work then you need a recovery [boot] cd of some type. Got a windows installation cd? You may need to run a Repair [via Setup].

I'd say the power supply failed.