No wireless networks found in range. Not connected

Hi all

Forgive me if you have read and seen this problem a million times before but I need an idiots guide to my wireless network and reading previous threads I am no better off as they don't seem to solve my problem.

I have had on and off problems with wireless:

1. I lost wireless protection some time ago when I was continuously seeing "acquiring network address" which i finally resolved a couple of months ago when I typed in the network key in capitals.  Typical

2. The latest saga (2am this morning) was when I i was advised to uninstall and reinstall Mcafee Total Protection (by McAfee tech support)  The McAfee Wireless Network Security programme within the package was able to search for available networks and was working perfectly until i uninstalled.  Now Mcafee no longer offer the package so am unable to reinstall it. 

like i said i need an idiots guide. I am currently connected through ethernet cable. which is fine but inconvenient. The wireless light on my dell inspiron 1300 computer is on (Fn+F2 has been checked) i have uninstalled and reinstalled my dell 1370 wireless network card 4 times in the last 2 years (as per dell troubleshooter). i have tried the network setup wizard and it has identified the network hardware (disconnected). i have even borrowered home network books from the library (including the For Dummies range) but hasn't solved it

other info: windows XP (think its SP3 now). broadband provided by sky. router is netgear (supplied by sky).  signal strength icon is also missing.

all suggestions welcome.