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I'm not sure exactly what you're trying here. It sounds like what you've done is copy the iso file to a disc-that won't do anything useful for you. What you must do is to burn that image to a disc. How you'd do that depends on what software you have handy (and what computer you're using-on a Mac, you can do it using Disk Utility).
And remember, in order to work properly, a Windows Install disc for a Mac MUST ALREADY HAVE SP2 INTEGRATED INTO IT. It may actually run without this, but it won't "work" after the install finishes. For a PC, it's also safer to have SP2 integrated before you start-a Windows computer that's connected to the Internet but not protected by SP2 could be "found" by any number of malware sources and attacked in a matter of minutes. It's best to just "slipstream" the SP2 download into your XP install disc-take a look at the
slipstreaming thread in our reference stuff. It's fairly easy, pretty much painless, and prevents a number of rather unpleasant problems. It only requires that you have access to a Windows computer that has a CD burner, and only for something like 30 minutes max.
Let us know how things go for you, and again, Welcome!