cannot be installed on Macintosh hd

Hello, ryan4595. Thank you for posting on the Apple Support Communities. You’ve come to the right place to get help with updating to macOS Monterey. 

We understand your situation and how you are seeing an error message when you attempt to start the macOS installation. We know that you must be eager to start using the new features in macOS Monterey and we are happy to help you with this. 

We’re glad to see that you have already started on the Apple Support article that explains how you can upgrade macOS. To continue from here, we have several more articles that we think will help you. 

To get started, it would be helpful to confirm that your Mac has enough storage space available to install the latest updates. Monterey may require up to 44GB of available storage. You can review the following article for information on how to free up additional storage space:

Free up storage space on your Mac - Apple Support

If you already see that your Mac should have enough space available for the update, we can help you more. To continue, please confirm that your Mac is on the list of compatible devices: 

macOS Monterey is compatible with these computers - Apple Support

If your Mac is compatible, we would suggest completing these troubleshooting steps before attempting to upgrade again: 

If an error occurred while updating or installing macOS - Apple Support

We hope that these suggestions allow you to install the latest macOS updates to your device. Please reply back here if you have any additional questions. 

Have a great day!