Having been CEO of software development firms, without hesitation I can say the reason any version other than QuickBooks 2010 is not compatible with Windows 7. A decision was made by Intuit (in Intuit speak, Policy) that in order to increase sales, Windows 7 was evaluated by the developers and when problems were found, the decision was made that rather than correct the issues, Intuit would force users to upgrade. This is solely a way to increase sales thus generating revenue, and nothing more. In reality, any and all compatibility problems can and should be resolved. A software development company that is customer driven as opposed to those purely revenue driven would test and correct operating system conflicts. I can assure you that a customer satisfaction driven company is also able to generate additional revenues without the backdoor approach of "forcing" a customer to upgrade at an inconvenient time of the fiscal year. A satisfied customer will upgrade and revenues will increase.
Accounting is critical to the operation of all businesses, and doing a software upgrade at any time other than the end of a fiscal year is not a sound business decision. In addition, QuickBook?s software is notorious for bugs in the first year of release. My companies will not upgrade QuickBooks until the software has been in production for one year, meaning we will always be running one version behind the current version. I have obtained a copy of the ?Software Bug Report for QuickBooks Pro 2010? dated 8/10/2010, and can assure you there are numerous problems that have yet to be addressed.
As one of my companies has addressed this compatibility problem we have found Intuit to be the only company not willing to assist a customer that is put into a bind due to operating system upgrades. Accounting is critical on a daily basis, and surprises cannot be tolerated.