Install Verita Exchange Agent in Exchange 2000 Server.

Make sure that the user you are using is a local administer of the machine.  To do this right click on My Computer and choose "manage".  Then expand Local Users and Groups and click on Groups.  In the right hand pane right click on Administrators and select Add to Group.  Then click on Add, select your domain from the drop down box and add in the account you're using to do the install with.