How do I access my imac with OS X base system showing, which it says is locked. It doesn't find the HD when I try an install from Time Machine.

• Select the top most drive device (Hitachi HDT...) and click the Erase button to erase and format the device.

• Name the device "Macintosh HD". Select "Mac OS Extended (Journaled)" as the format and "GUID" as the partition map scheme, then click the Erase button at the lower right.

• When Disk Utility reports the task done, quit Disk Utility and return to the macOS Utilities window.

• Select "Reinstall macOS" and click "Continue". Follow the prompts to reinstall the OS. Select "Macintosh HD" as the drive to install to.

Welcome to the Apple Support Communities.

I have multiple questions first:

1. What year is your Mac?
2. What version of macOS are you running?
3. What did you do to get in to this mode? Did you erase your Mac?
4. In Mac OS Recovery, can you go to Disk Utility, and select "View" > "Show All Devices" (if shown). Select each device (or entry shown), and take a photo of it and upload them all here. 

Cheers,

Jack

Data migration doesn't affect the source machine, just copies data over. It should have run after migration just like it did before migration.

Upgrading to a newer OS is dependent on the latest it can run and what you have running now. But that process is standard and unchanged.

Thank you. So, since you Migrated to a new Mac, what are you trying to do with this 2009?

You're welcome.

Glad you sorted it out. 🙂