issues with wireless card download upgrade

I have an Inspiron 6400 and have recently been having wireless connection problems. I was told that my wireless card needed updating (I have a 1390 WLAN wireless card, dated 2006). I found the download on the DELL website but when I tried to download it, the following error occurs:

Cannot continue. The application is improperly formatted. Contact the application vendor for assistance.

I contacted DELL support however there is a service fee involved which unfortunately I can't afford :( Is anyone else able to help me with this one?

Thanks in advance!