Hi Tim
The latest version of Word is Word 2003. It requires Microsoft Windows 2000
with Service Pack 3 (SP3), Windows XP, or later. You can't go and buy a copy
of Word 2000 or earlier in a retail store. You may be able to buy an old
copy second hand, but you would need to check carefully that you are buying
software that you may use legitimately.
As far as I know, the ability to "downgrade" to an earlier version of the
product depends on your business having a Volume Licensing arrangement with
Microsoft.
I suggest you ask your IT department or, failing them, the people from whom
your business buys its software licences.
Hope this helps.
Shauna Kelly. Microsoft MVP.
http://www.shaunakelly.com/word