I don?t know the answer but some things that you can try are:
- Reinstall / Repair the Office 2003 Pro Edition. Maybe you have several
Office versions installed.
- Try in another machine to see if it is something specific to your machine.
- Use monitoring tools such RegMon and FileMon
(http://www.sysinternals.com/) to monitor what the setup is checking to know
if Office 2003 Pro Edition is installed and why is failing in your machine.
With this info you can contact Microsoft Support to solve the problem.

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Carlos J. Quintero (Visual Developer - .NET MVP)
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> When I try to install Visual Studio Tools For Office I get a msg (as soon as
> I insert the CD) telling me that before I can install VSToolsForOffice, I
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>
> Thanks, Paul628. Original posting June 10, 2004. Re-posted 6-28-04