One of the most important function keys available in QuickBooks is the F2 key. It provides crucial QuickBooks information.
The F2 key opens up the Product Information dialog box (also accessible using the combination of CTRL + 1 keys).
Within this dialog box you can find the license number and product number. A copy of these numbers should be stored elsewhere in case the need arises.
Other important information found here is the company file size. A large file size is a good indicator that it may be time to upgrade QuickBooks Pro or Premier to QuickBooks Enterprise Solutions, for example).