Thexder Installation To run the Thexder demo you must have Windows 95 installed on your computer. Switch to the CD drive then double click SETUP from the Thexder directory. After running setup, double click the THEXDER.EXE icon. The demo will automatically start up. Should you have any problems running the demo, please contact Sierra’s technical support department at (206) 644-4343, Monday through Friday, 8:15 to 4:45, PST.