Outlook 97 not launching in Windows 2000

I added users to “Group User” and they cannot launch Outlook to access their email. But when I add the users into the “Power Users” group, Outlook launches and users are able to get to their email.

This only happens on Windows 2000 Pro. PC andI am trying to prevent users from making any changes to the PC.

Need some advice how I can limit users access and still make Outlook work.