As part of evaluating Microsoft Search Server 2008 as an intranet search tool, I wanted to modify its crawler’s user agent string in order to trivially monitor it in our web logs.
I couldn’t find any documentation on this, but eventually came across a registry entry which controls it:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\12.0\Search\Global\Gathering Manager\UserAgent
Modifying this (using Start->run->regedit), and restarting the search service (Start->Administrative Tools->Services->Office SharePoint Server Search) then resulted in the crawler using the text I’d entered as its user agent.
