Dear ATR
Thanks for your answer - I am coming from a company with a volume license agreement and silent installation of PRE 12 works fine. The only problem is as mentioned the UAC when MPEG2 Component activation happens (during/after rendering). If a "normal" user cancels the UAC (trying to register the two files C:\Program Files\Adobe\Adobe Premiere Elements 12\mc_dec_mpa_ds.ax and C:\Program Files\Adobe\Adobe Premiere Elements 12\32\mc_dec_mp2v_ds.ax), rendering works anyway and no UAC appears in future!? Giving the necessary permissions on this files doesn't work...
Unfortunately Adobe Chat for me is unusable!
Thanks for any further suggestions.
Andreas