Two versions again-language issue

WinXP Pro
My main installation is Office 2003, English, working as it should,
including Word as my Outlook editor.
Occasionally I need to write in another language (Czech) for which I only
have Word 2000.
Both are installed on the HD.
When I need to run it (Czech Word 2000), it goes through a partial
installation by asking for the CD. After it does what it wants (few seconds)
it is installed and working properly.
But, when I go back to Word 2003 it goes through the same installation
routine. Since I have Office on the HD it is not a major problem, except
that Outlook complains it cannot find its default editor ...

My question is how to adjust my installation so that both versions coexist
peacefully with each other without having to reinstall them after every
switch.
Thank you.

Otto