Your File Exchange control panel only gave you Entourage to open sit files? 1st you need to have stuffit or stuffit expander on your computer. Next, Open File Exchange control panel, Hit the PC Exchange tab, make sure both the Open PC extentions ect... and Open unmapped files ect... boxes are checked. Now scroll down the list for PC extention to SIT If it is not there you can make one by hitting the add button, if there is one it should be set to stuffit expander. You can change it by hitting change button. Either way the same boxes come up next. If all goes well the change button a search for applications window comes through with stuffit expander among your choices. If you are adding type SIT in the Extension: (top box) Now scroll down to suffit expander or hit the select button and go to stuffit expander and select it. Next set the File Type: to SITD if it is not already set for you. For the rest you may need to hit the Show advanced options box or it may allready be in the right half of your window. Here goes Set Name: Stuffit Archive Mime Type: application/x-stuffit Check both Map Incoming And Map Outgoing. The Data Format is Binary Data and the Handle by: should be set to Processing with application Application: Stuffit expander. Hope this all helps.