Did it come pre-installed on your computer? If yes, the OEM will have
provided some way for you to reinstall it. Check the system's documentation
or the computer manufacturer's website for directions.
You do realize, WordPerfect is not only not a part of XP it isn't even a
Microsoft product. As Sharon has stated, if it came bundled with your
system, you need to talk to the manufacturer's tech support about how to
restore items for which they didn't include a setup disk.