You configure a Microsoft Office Excel 2003 workbook so that multiple users can make changes to the workbook at the same time. You upload the shared workbook to a document library in Microsoft Office SharePoint Portal Server 2003 or in Microsoft Windows SharePoint Services. You find that only one user at a time can check out the shared workbook from the document library and make changes to it. Multiple users cannot make changes to the shared workbook at the same time if they open the workbook from the document library.

This behavior occurs because only one user at a time can make changes to a document that is stored in a document library in SharePoint Portal Server 2003 or in Windows SharePoint Services. A user must check out a document from the document library before that user can make changes to that document. If a document is checked out by one user, other users have read-only access to that document. Other users cannot change that document or see the changes that are made to the document until that document is checked in. After the document is checked in, another user can check out the document and make changes to it.

By design, SharePoint Portal Server and Windows SharePoint Services work this way. This behavior occurs for documents that are stored in document libraries, including shared Excel 2003 workbooks and other document types that support an option where multiple users can make changes to the document at the same time.

If a user checks out a document, makes changes to it, and then later decides that they want to check in the document without saving their changes, the user can undo the check-out operation. Changes that the user made while the document was checked out are not saved. The document reverts to the last checked-in version. For more information about document check-in and document check-out, see SharePoint Portal Server 2003 Help or Windows SharePoint Services Help.