Mail merge has stopped working with Excel input

[Myrna]

I am using Word 2003 on a windows XP PC.

A few days ago, a mail merge using an Excel file of data has stopped
working. It only works when I use an Access file for input. When I select an
Excel file, a window titled 'Data Link Connection' pops up. Did I set
something somewhere that tells Word I only want to use Access? I don't see
any place to fix this. Can anyone help?

I've removed Office and reinstalled it. I can do this on other PCs on my
network.