shapefile coordinate system data

[StephenDowd]

Arcgis explorer give me error message "unknown coordinate system" when trying to import shapefile triplet (.shp, .shx, .dbf). I do have a document describing the PE but would like an example of the kind of file I need to include with the existing triplet. Would this be a .prj file? An example of the content for WGS-84 UTM 28N would be appreciated.
Paul

[JoeFlannery]

Stephen:
Yes, you do need a .prj file if you expect ArcGIS Explorer (or ArcMap) to reproject your data on the fly.  If you are using ArcMap, you can find prj files here:  C:\Program Files\ArcGIS\Desktop10.0\Coordinate Systems\   Alternatively, if you do not have a prj file with your shapefile "triplet", you could change the map projection in AGX to match the projection of the shapefile.

See attached zip file for the projection file you are looking for.

[StephenDowd]

Joe,
Many thanks - looks like what I need.
Paul