Barbara G --
From the context of your question, it sounds like you are using Project
Server 2007. If this is the case, in future please post your Project Server
questions in the microsoft.public.project.server newsgroup, as this
newsgroup is dedicated to the Microsoft Project desktop application only.
To answer your question, you have several choices:
1. If you no longer need to view the project data in PWA, your Project
Server administrator can do an Administrative Backup of all projects, which
will save them for historical purposes in the Archived database. He/she can
then to delete completed projects from the Draft and Published databases,
which will leave the backups in the Archive database. If anyone ever needs
to see the deleted project again, he/she can restore the project for
viewing, and then delete it again as needed.
2. If you need to continue to see the project data in PWA, then your
Project Server administrator can use a solution similar to the following
FAQ:
http://www.projectserverexperts.com/ProjectServerFAQKnowledgeBase/ArchiveCompletedProjects.aspx
Even though the above solution is specifically or Project Server 2003, it
will also work for Project Server 2007 as well.