QuickBooks Enterprise/Premier/Pro/Accountant 2004-2017
With QuickBooks open, press F2. QuickBooks will display a Product Information window. The first line of the Product Information window gives the QuickBooks product version followed by the release number RnP (where n is the release number).
Alternatively you can hold down the CTRL key and press the number 1 (CTRL+1). Use the number one key at the top of your keyboard rather than the one on the number pad to the right.
QuickBooks 2003 and older
With QuickBooks open, hold down the CTRL key and press the number 1 (CTRL+1). Use the number one key at the top of your keyboard rather than the one on the number pad to the right. QuickBooks will display a Product Information window. The first line of the Product Information window gives the QuickBooks product version followed by the release number.