Check out this MS Technet Article for command-line switches that are quite often just what you need:

<A target="_blank" HREF=http://support.microsoft.com/support/kb/articles/Q197/1/80.ASP?>http://support.microsoft.com/support/kb/ar...s/Q197/1/80.ASP?</A>

Most also work in Outlook 97 and 98.

In Outlook 97 and 98, there is a /regserver command. In Outlook 2000, the comparable command is /cleanprofiles