I'll fix that in a moment but here for Dell I go to dell.com and enter my service tag to get to the drivers I need for my dell.
Long story short, if your wireless adapter doesn’t work or you accidentally deleted it, go to your manufacturer website example: www.dell.com , sign in, and download you missing or malfunctioning driver or adapter. This is the ultimate solution when the updating method dosen’t work. (Please feel free to ask further questions I would love to help out because I was in the same boat)
Moderator note: Dead link. Fixed it.