Not sure, but Dell's Support site has a Windows 7 driver for the Wireless WLAN 1397 Half MiniCard (4312bb) dated 11/17/2009.  My guess is Windows 7 came out before the driver was compiled and therefore it doesn't recognize the card as being on the HCL (Hardware Compatibility List). 

For Windows 7 64-bit

http://support.dell.com/support/downloads/driverslist.aspx?os=W764&catid=5&dateid=-1&impid=-1&osl=EN&typeid=-1&formatid=-1&servicetag=&SystemID=INSPIRON1545&hidos=W732&hidlang=EN&TabIndex=

For Windows 7 32-bit

http://support.dell.com/support/downloads/driverslist.aspx?os=W732&catid=5&dateid=-1&impid=-1&osl=EN&typeid=-1&formatid=-1&servicetag=&SystemID=INSPIRON1545&hidos=W764&hidlang=en&TabIndex=

-DaveB!

Thanks DaveB for your reply, much appreciated.

I took a chance the other night and removed the 1397 card, and thus installed windows7, and lo and behold, when I completed the installation, I connected up to the internet, via my wireless router with no problems at all!!!!

I assume that there are drivers in the upgrade that do the job!

So if anyone else has this problem take heed.

Brian

I assume that there are drivers in the upgrade that do the job!

Windows 7 has a far more extensive and up-to-date drive base than Vista had/has Brian, and is subsequently able to recognise and install drivers for a much wider variety of hardware by default :emotion-5: