It is undocumented on Microsoft's website, or, at least to the extent that the various pages that I encountered that lectured me on how evil I was to be using pirated software and how I would have to give Microsoft $149 to "make genuine" MY ALREADY LEGAL, FULLY GENUINE, VALIDLY LICENSED SOFTWARE, had absolutely nothing about this.

In my situation, I had no idea is a system command (or software installed in the system root) -- all I knew was that it was missing from my system tools menu. I assumed I'd have to install something from the original installation disks or, alternatively, that Microsoft would give me an address on the Microsoft site to download it.

Notwithstanding, I'm not running undocumented commands based on someone's webpage instructions I found after a google search unless I know the source very well. For that matter, I can also find all sorts of validation deactivation instructions (which, by the way, and notwithstanding your previous post, do not violate any law, including the DMCA -- it is completely legal to provide those instructions though I will, of course, abide by all instructions from moderators, as well as flight crew and for the same reasons) by using Google but, again, they all entail downloading software that install registry hacks, access system root software, and a variety of other things that, even if scanned by my antivirus software, can still do signficant damage if malicious.