You have One lisence for Poser 5. You can install it on any computer that suits you but you must remove it from the other. You should be able to exit Poser by using the File exit command. If that is greyed out are you sure that the file export is complete. Exporting the geometry for a modified figure may take several minutes. When you export keep an eye on the drive light and wait for it to stop or open windows explorer and check that the file has been written out. You should not lose the contents of the libraries by doing a new install but it might be a good idea to rename the original runtime folder, reinstall poser and then putting the stuff you have created back. If you are changing thing in the cr2 files it is always a good idea to work on a copy. That way you always have the original if you mess it up.