I recently started hacking a 1545 for a friend and accidently installed some kext. It was two am so I went directly into the kext exstentsions folder and deleted it. I rebooted it and the wifi didn't work. I reinstalled the package it came in; no luck. Installed Snow Leapord again; still no luck. Made a new CD which I was booting from; NO LUCK! Please help me!

I got this to work. I reinstalled Windows 7 and reinstalled the BIOS from the Dell Support Website. Hope this helps.