Latitude E6400 Privacy Screen Filter (Software Based)

Hi,

I know that the E6400 is a dated system, but I have dug my out of the closet and turned it on. I had to re-image the system because the hard drive has failed.
Regardless, I remember a feature when if I pressed a FN + E the software-based privacy filter [screen obscured if viewed from sides and not from straight in front of the integrated display] would activate. My question is, because I have re-imaged the system, what version of ControlPoint or other software do I need to install and where can I download it?

There's a dell blog entry discussing it: 
http://en.community.dell.com/dell-blogs/dell4enterprise/b/dell4enterprise/archive/2008/10/16/latitude-e6400-software-privacy-filter-transition-to-leds-premium-panels
Somebody made a YouTube video demonstrating it (starts @ 2:58):
https://youtu.be/yx6HzLTrHB8?t=2m58s

I can't seem to find the software and it's a really cool feature.

Many thanks in advance,

-Sergio