As a matter of fact, you must convert it to PC as long as your Mac files are still on a Mac harddisk, but the resulting files are "PC ready" afterwards, so there will be no need to perform another conversion after they are extracted on a PC. Maconverter converts all sorts of Poser files - it creates the PC only .rsr files for all libraries (including lights, of course) and for Geometries .obj's (if your package includes some). In this case you can also encode it to .pcf (if your .obj's are built from copyrighted originals) to avoid copyright infringement. It also makes sure that all files are correctly named for the PC. The Aladdin expander only expands, for zipping you need DropZip (which is shareware) or the full StuffIt Deluxe - which is a bit pricey, but great. You can open and edit StuffIt archives with it, which is very useful, couldn't live without it...