The my old hard drive containing llightroom crashed? How do I re-install it into my new hard drive? I use an iMac with El Capitan software.
You can download and reinstall from here: Download Photoshop Lightroom
What is your version of LR? Subscription or perpetual?
How about the catalog and the images? Were they on a separate drive or do you have a proper backup?
Retrieving data ...