Windows 7 64 bit - Audacity 2.0.5 - Seeking to save preferences for all users. Logged onto system as administrator.
Reading the Audacity wiki - I do not find the settings indicated - http://wiki.audacityteam.org/wiki/Lame_Installation#All_users
Launch Audacity, click Edit > Preferences then the File Formats tab. ( I find Edit / Preferences, but the trail ends there).
Look for the MP3 Export section.
I have installed the lame_enc.dll in the directory with Audacity without any visible change to the issue.
What our user wants is:
DLL files for Audacity need to install - do this once and never again.
Set export to mp3 file as default in Audacity
I have yet to discover how one does this.