Ubikcan wonders why ArcReader requires such a powerfull PC to work. Simple, it is pretty much full blown ArcGIS minus all the features. I’d expect ArcExplorer to be much easier on the systems than ArcReader. Still, the point of a reader program is that you don’t need a full blown GIS system. If ArcExplorer supports PMF files, I’d say Reader is pretty much dead anyway.