When you click to open a company file, you see the message "QuickBooks is not responding." The computer appears to be locked up and the cursor is an hour glass.
When you see this condition, the Task Manager may indicate that QuickBooks is not responding. Do not click End Task until at least ten (10) minutes have elapsed to be sure that QuickBooks will not continue.
A possible cause is that your Memorized Transaction list contains damaged memorized transactions.
Test a sample company:
Troubleshooting damaged memorized transactions: