Google Desktop Search v2 lets you search Thunderbird email and Web pages you've viewed using Mozilla 1.4+ and Firefox. But if you install Mozilla Firefox after you install Google Desktop, Google Desktop will not be able to find your web history cache and you won't be able to use GDS for searching web pages visited from Firefox.

Here's how to fix the problem. Google Desktop should begin indexing your Firefox web history.

1. Open the C:\Program Files\Google\Google Desktop directory.

2. Select the three GoogleDesktopMozilla files in this directory.
GoogleDesktopMozilla.dll
GoogleDesktopMozilla.png
GoogleDesktopMozilla.src

3. Copy these files to C:\Program Files\Mozilla Firefox\components

4. Close Firefox.

5. Delete the compreg.dat file located in the following directory:
C:\Documents and Settings\%USERNAME%\Application Data\Mozilla\Firefox\Profiles\[RANDOM]

6. Restart Firefox

See similar instructions for Mozilla or Thunderbird email program.