Type Mac OSx Windows XP Windows Vista
Application In the Applications folder In the \Program Files\Adobe\Adobe Photoshop Lightroom 2 folder In the \Program Files\Adobe\Adobe Photoshop Lightroom 2 folder
Preferences In the [username]/Library/Preferences folder: com.adobe.Lightroom2.plist In the Documents and Settings[username]\Application Data\Adobe\Lightroom\Preferences folder: Lightroom 2 Preferences.agprefs In the Users[username]\AppData\Roaming\Adobe\Lightroom\Preferences folder: Lightroom 2 Preferences.agprefs
Catalog In the [username]/Pictures/Lightroom folder: Lightroom 2 Catalog.lrcat In the Documents and Settings[username]\My Documents\My Pictures\Lightroom folder: Lightroom 2 Catalog.lrcat In the Users[username]\Pictures\Lightroom folder: Lightroom 2 Catalog.lrcat
Locks In the [username]/Pictures/Lightroom folder: Lightroom 2 Catalog.lrcat.lock In the Documents and Settings[username]\My Documents\My Pictures\Lightroom folder: Lightroom 2 Catalog.lrcat.lock In the Users[username]\Pictures\Lightroom folder: Lightroom 2 Catalog.lrcat.lock
Preview data In the [username]/Pictures/Lightroom folder: Lightroom 2 Catalog Previews.lrdata In the Documents and Settings[username]\My Documents\My Pictures\Lightroom/Lightroom 2 Catalog Previews.lrdata In the Users[username]\Pictures\Lightroom\Lightroom 2 Catalog Previews.lrdata
Backups In the [username]/Pictures/Lightroom folder: Lightroom 2 Catalog.lrcat in it’s own folder by date In the Documents and Settings[username]\My Documents\My Pictures\Lightroom folder in it’s own folder by date In the Documents and Settings[username]\My Documents\My Pictures/Lightroom folder in it’s own folder by date
Presets In the [username]/Library/Application Support/Adobe/Lightroom file names ending in .lrtemplate In the Documents and Settings[username]\Application Data\Adobe\Lightroom folder with the file names ending in .lrtemplate In the Users[username]\AppData\Roaming\Adobe\Lightroom folder with the file names ending in .lrtemplate
Registration In the [username]/Library/Application Support/Adobe/Lightroom/Lightroom 2.0 Registrations Data\Adobe\Lightroom\Lightroom 2.0 Registration.lrreg *C:\ProgramData\Adobe\Lightroom\Lightroom 2.0 Registration.lrreg *

Replace the [username] with your logon ID