problem with Word 2003

I just got a new machine with Windows 7 installed. I deleted the installed trial version of Office 2007 becuase I own a copy of Office 2003. I installed Office 2003, and it seems to work fine (no Outlook Express though), but when I type a Word document and use the "look up" feature for a particular word in the text, it does not work. It shuts down Word and saves the document in the recovery utility. I use the look up feature often for meanings and origins of words, and really want it to work. Any ideas?

What exactly do you mean when you say deleted?

Did you delete Office 2007 from "Program Files" folder?
or
Did you use the uninstall method in "Programs and Features"?

I would try starting up the 2003 installation tool and selecting Repair Installation or similar from the menus... After that, make sure you have all the patches and SPs for it from Microsoft Update.

Downgrading Office has never been the smoothest of experiences for me...

I used the utility in Control panel for removing programs. I did not delete it from the program files. Thanks,
Randy

Did you go to Windows Updates and download all the updates for it?

There are a lot of them... around 100MB or so.

Just be sure you've enabled the "Updates" to use Microsoft Updates too.