(Case 00342895)
Hello Hilbert,
If the flies in question have a .flp or .flipchart extension, the ActivInspire software can be used to open those files. That software can be downloaded from Promethean Planet in a variety of languages through this page.
If the ActivInspire software is already installed and the files are not opening, please advise us of any error messages or other behaviour presents when attempting to open those files.