The system requirements have changed for QuickBooks 2009. It does not work on Windows 2000. Make sure your computers are upgraded before you install. Here is a link to the system requirements. http://quickbooks.intuit.com/product/accounting-software/small-business-accounting-software.jsp
Operating Systems supported:
Windows XP (SP2 or later strongly recommended), all editions
Windows 2003 Server
Windows Vista (w/UAC on), all editions
Windows Longhorn Server (database only, not client)
