Second Life has a few important files:
- secondlife.exe - client
- settings.ini - preferences
- colors_base.ini - UI colors
- colors.ini - custom UI colors
- custom_keys.ini - avatar keyboard controls
- viewerart.ini - viewer UI, texture, and sound asset keys
These files, along with ~10MB in the ..\app_settings\mozilla\ folder, increased SL's installer by ~5MB (to ~25MB) and installed (uncompressed) size by ~20MB. An ever-increasing client doesn't make testing preview releases fun since the entire client is mindlessly redownloaded for each new build instead of SL having a more intelligent patch system whereby only relevant files are updated ("patched").