Latest questions about "quickbooks premier nonprofit edition 2011"

I am trying to install QuickBooks Premier: Nonprofit Edition 2011 on a computer with Windows 7. Is this edition compatible with windows 7?

I keep getting a message that "The attempt to log in with the user name failed. This user is already logged into the company file." I am the only one who has access and I just don't know what to do.

I downloaded the application but I cannot install it without the product key. Can you help?