While John has hopefully found the answer by now, I'm posting this solution that worked for me to help others who are out there hunting!

download

---While the file description says it's for xp 32 or 64, it worked with Windows 7 64-bit

run custom install

uncheck all devices except Broadcom Unified Security Hub

restart computer when prompted

note that the desktop doesn't appear until after the install completes it's post-rebot configuration - don't panic

Broadcom USH moves to a new device category called Credential Vault Device

Microsoft update will upgrade driver if/when available

You will find the Broadcom USH driver in the security list for the E6420 www.dell.com/.../LAT_E6400

i tried the link you supplied but got a message that that page could not be provided any longer.

I am trying to decide if I really need or use the Broadcom USH driver, or will need it.

I found some info on the web site that it is included in the Control Point Device Driver Package, but, I do not know that I really ought to install that whole package if I do not use a security card system to access my machine or my network.

Can you give me any suggestions as to how I might know what I need and how much to download and install.