The latest Dell Driver for the Dell Wireless 1704 Card is 6.30.223.228. You may also try the later Dell Wireless 1708 card 6.30.223.245 (both are Broadcom rebundled drivers) first directly and then through the device manger.
Hello everyone!  I have a Dell Inspiron 3521. It had Windows 8.1 on it and I installed Windows 7 Pro OEM 64 bit. I did delete the old windows file. I was able to install all the drivers from the Dell website, but I can't seem to figure out how to get the right driver for the "Network Controller". I tried Driver Identifier and it shows me two drivers missing: 1: BCM43142A0, 2: Network Controller.  Here are the hardware IDs for the NC:  PCI\VEN_14E4&DEV_4365&SUBSYS_00161028&REV_01PCI\VEN_14E4&DEV_4365&SUBSYS_00161028PCI\VEN_14E4&DEV_4365&CC_028000PCI\VEN_14E4&DEV_4365&CC_0280  I did find a post with someone having the same keys, but the driver in the link didn't help me. Maybe it's the way I installed the drivers? Or the way I installed windows 7 ?  Please help!!!
I need help, I tried everything! Network controller after installing windows 7 
on a windows 8.1 machine!