I can provide the last update of the investigation given to us by our Product Team about the issue, major41501.

We recommend you to use QuickBooks on another system or in selective startup to troubleshoot their own systems. This is due to the Microsoft SQL installed on your current computer.

If you don't want to use another computer, you can temporarily uninstall the Microsoft SQL. Then, install it later after setting up ne To Do task.

Let me outlined again the steps on how to set up a reminder.

1. From the File menu, select New Company.
2. Choose Start Setup and fill out the required fields.
   
3. Click the reminder icon, then select the + (plus) sign.
   
4. Enter the necessary information to complete the task.
   
5. Click OK.
   

Also, QuickBooks Desktop allows you to use payment reminders to schedule statements for your customers. Here's a link to guide you through the process: Create automated payment reminders for invoices and statements.

Don't hesitate to post again if you have other QuickBooks concerns or if you have follow-up questions about setting up a new To Do list. I'll be right here to help you manage your company file.