." Does this mean that people with more than one computer, particularly if running on different OS's, need to buy more than one copy?
The current version of DW (i.e. version 4.2) will work on OS 10.3.9 or later. If you have it installed on an external drive, you can (hopefully) boot from that drive and run DW on the internal without violating the license agreement. Of course, the OS version on the external has to be able to boot the computer in question! For example, if the external has 10.4 and you intend to boot a computer that originally came with 10.5 or later, you won't be able to do it.
the other query I have is that I noticed that in one set of "Installing" information it advises that "Before installing DiskWarrior you should start up from the DiskWarrior disc and rebuild all of your disk directories with DiskWarrior. This will eliminate any existing disk damage.", whereas on another .rtf no mention is made to that effect.
It's not a bad idea. I did exactly that before I installed DW on my internal. It can take 5 minutes or longer to boot from the DW CD so be patient. FYI, I run DW from a second internal hard drive that has a bootable clone of my main drive.
To allay some of your fears, I have used DW for many years and swear by it. It has gotten me out of hot water several times. I really like Alsoft's philosophy, similar to Hippocrates, to "first, do no harm". When you click the Rebuild button, DW goes through 9 steps before giving you an option to make changes. In other words, nothing actually happens until you go to step 10. Unless you have OS 9 drivers installed, it skips steps 2-4 so don't be alarmed if you go directly from 1 to 5.
At the end of step 9, you get an opportunity to preview its proposed changes. You can examine a Before and After scenario and move items from one to the other if something seems amiss. Then, you have the option of letting it rebuild the directory or canceling. DW has never let me down.
