If you have a multi-user version of QuickBooks, some situations cause QuickBooks
to run slowly when two or more users are working in your company file.
Important: For the best performance in multi-user mode,
be sure to install QuickBooks or the QuickBooks Server on the same computer
where the company file is located and set up that computer according to the recommended multi-user setup.
For tips on what you can do to improve slow performance, see these topics:
Where to store your company file
Tips for day-to-day
operations
Tips for reports
Tips for printing
QuickBooks Enterprise Solutions offers 
enhanced multi-user performance.
See also