Greetings, @Harkins45.
Welcome to the QuickBooks Community. I'm happy to help share the steps on how you can update or convert QuickBooks Desktop 2003 to QuickBooks Desktop 2018.
Before we start, please take note that only the company Admin can update the company file and once it's updated, you can no longer open it to the previous version.
Here's how:
- Open your new version of QuickBooks Desktop.
- From the File menu, select Open or Restore Company.
- Select Open a company file then click Next.
- Highlight your data file then select Open.
- Read the info in the Update Company File for New Version pane.
- Check the box to signify you understand, then select Update Now.
- Follow the instructions on how to create a back up of your company file then please take note where you save it.
- When You are about to open a company file using a newer version of QuickBooks...Do you want to continue? appears, select Yes.
For more details, I recommend checking this article: Upgrade or convert your company file to a new QuickBooks Desktop version.
Also, feel free to reach out to our phone support if you need additional help. They can initiate a screen sharing session to assist you in the whole process.
Here's how you can reach them:
- Go to: https://help.quickbooks.intuit.com/en_US/contact.
- Choose your QuickBooks Product.
- Select your QuickBooks version.
- On the Contact Us page, click a topic.
- Click on the Get Phone Number button to see the support number.
That should do it. Drop me a comment below if you have any other questions about upgrading your company file to a newer version. Have a great day.