I can share details of why the installer isn't available, RMR9.

Your Quickbooks Desktop 2009 Pro is no longer supported that's why it isn't available. 

You may consider upgrading the version of your software to keep your business up and running. If you need help installing the upgraded version, you can find the complete guide in this article: Install QuickBooks Desktop.

After installing, you can browse articles from our Help page if you need help getting things done in future tasks to your account. 

If you have follow-up concerns regarding the installation, don't hesitate to post again here. I'll be glad to help you more.