Is there a way to cleanup perfs.js? I was looking at the file, 3788 lines, that contains printer information for printers that do not exist. I've been using TB over 24 years and it has grown through four systems. A system replacement involves a new CPU, mother board and C: drive. Data exist on other drives that are moved. Sometimes the content is copied from old drives to newer faster larger drives. References to software that no longer exists user_pref("plugin.flash.path", "C:\\WINDOWS\\SysWOW64\\Macromed\\Flash\\NPSWF32_32_0_0_465.dll"); Some sections look like they have been replicated further down. Entries that look like they have accumulated over time. user_pref("mail.smtpservers", "smtp50,smtp32,smtp52,smtp45,smtp10,smtp38,smtp19,smtp25,smtp39,smtp6,smtp24,smtp16,smtp33,smtp18,smtp9,smtp2,smtp29,smtp7,smtp1,smtp13,smtp17,smtp12,smtp5,smtp4,smtp3,smtp15,smtp20,smtp21,smtp23,smtp26,smtp27,smtp28,smtp30,smtp35,smtp36,smtp37,smtp40,smtp41,smtp43,smtp44,smtp46,smtp47,smtp48,smtp51,smtp53,smtp22,smtp8,smtp11,smtp14,smtp31,smtp49,smtp42,smtp54"); Also, is there documentation about the various entries in prefs.js? user_pref("mail.server.server1.ageLimit", 1); user_pref("mail.server.server10.ageLimit", 30); Just to mention a few. Thanks