Hi Aldrin,
Unfortunately that's an 'expected' behavior. You may, if you have a sufficiently hefty system, investigate running the older
version under a free MS virtual machine.
http://microsoft.com/virtualpc if dual booting isn't feasible.
The installing/configuring behavior isn't new to Word 2007. MS doesn't directly support running multiple versions of Office on one
computer, but does provide a procedure for setting it up if you need to
http://support.microsoft.com/kb/928091/en-us .
Prior versions of Word were very language and version centric. When you start them the MS Installer is called to reset registry,
DLL and other pointers to be of the correct version and language for a particular Word installation and in trying to match up to
Outlook where Word used to be used as the email editor. In addition, Word 2003 had two flavors of Word (Word 2003
standalone/Professional and Word 2003 all others). There's apparently more to switch back when going between Word 2007 and prior
versions of Word so the 'reset' to use the right files and registry links and file associations can take longer when 2007 is one of
the two involved Word versions.
==================
Hi,
I have installed Office 2003 Pro and Office 2007 Pro on the same machine
under the same OS (XP Pro). They seem to work fine except for one glitch.
This has to do with Word. When you start Word 2003, and then later start Word
2007, Office wants to reconfigure itself. Then later if you start Word 2003,
it wants to configure itself. They both work fine after the configure, but
they configure EVERYTIME you start one and then the other. This I believe has
to do with the fact that they use the same registry entries. BTW Word is the only app that does this. Excel. Powerpoint do not. >>
--
Bob Buckland ?

MS Office System Products MVP
*Courtesy is not expensive and can pay big dividends*