It had nothing to do with adm elevation, standard users could not start this script. By luck I had to reset the PC to a previous state (for an unrelated reason) using Win7 restore. Then it appeared that the .PS1 package (containing a certificate) had not been installed correctly the first time. Now standard users can start the script when the execution policy is AllSigned. Wowever, this doesn't resolve the problem for future scripts which will be issued by the local administrator…