To speak with QuickBooks Desktop support, dial 855-200-0590. When you call, you'll be greeted by an automated menu. Follow the prompts to navigate through options such as technical support, account inquiries, or billing. Provide any necessary account details when prompted. Hold the line until you are connected to a live representative. Once connected, clearly explain your issue or question regarding QuickBooks Desktop. The representative will assist you accordingly, providing guidance, troubleshooting steps, or further instructions as needed. It's helpful to have your account information ready to expedite the process.