network problem

hello

i have a hp laptop the model is 6750ea
and it has inbuilt intel 3945abg wireless card.

i formated my computer a few days after i got it and i installed the wireless drivers and it was working fine. it then a few days ago stopped finding any networks, i uninstalled the driver and re installed did not make a differance so i then formated thinking it would solve the problem so i did installed the drivers and it worked so i thought its solved it i then installed another driver for my video card and its stopped working it always comes up when i turn my laptop on that the "wireless network unavailable" and if i say search for a network it will say " no networks are in range"
also when looking at the show all network connections it has a red x on it even when it is enabled

does any one know what might have happened and how i can fix this

thanks for any help

ps sorry posted twice only just realised it was in the wrong place