prathapml, I figured it out! Ok, here is what I did. First I installed the theme I wanted with WininstallLE running in the background. This isolated the files that were edited and modified. Then through trial and error, I figured what I needed to do, which is the following: - Modified prefs.js like you suggested - I copied a random name folder (which we will call ABC123 for this exercise) from C:\Documents and Settings\<username>\Application Data\Thunderbird\Profiles\RANDOM.default\extensions (should be the only one) and the extensions.rdf file into C:\Program Files\Mozilla\Thunderbird\defaults\profile\extensions (over-write the existing extensions.rdf) - Then using an xml viewer program, I opened the chrome.rdf in C:\Documents and Settings\<username>\Application Data\Thunderbird\Profiles\RANDOM.default\chrome and modified all the entries that pointed to the ABC123 folder in the "Documents and Settings" to point to the ABC123 folder in its new location and saved it. - Then I opened the modified chrome.rdf in notepad and copied all the information (leaving out the file header information) in the file. I pasted this at the end of the default chrome.rdf located here: C:\Program Files\Mozilla\Thunderbird\chrome - Finally, using WinRAR, I created a silent .exe file containing the following: C:\Program Files\Mozilla\Thunderbird\ chrome\chrome.rdf defaults\profile\prefs.js defaults\profile\extensions\ABC123 (whole folder) defaults\profile\extensions\extensions.rdf I made sure it extracted correctly, over-writing all existing files. I run this after installing Thunderbird. Now, here is the only downside: This puts the new theme in the theme list (so you now have two), but you cannot use the default theme anymore. Even if you select default from the Theme menu, click Apply and restart, Thunderbird will use the new theme. But, this is fine by me! Hope this helps someone else out, and thanks for all your help prathapml! My Unattended Win XP Pro W/SP2 is now complete!!! John