You can't install the software without an original CD to verify legitimate use, although there is a trick that sometimes works for getting around it by burning the software onto CD or a thumb drive, and naming that CD or drive the same as the original software (S-SW110 for my K-5). I had success with this trick on one computer but not one a second where I had legitimately installed an earlier version of the Pentax DCU prior to my CD being destroyed by my kids.
I'm currently playing with FastStone Image Viewer and PhotoScape which both seem to run quickly. Not sure what resources they require though.
Last edited by MSL; 03-15-2012 at 03:52 PM.