When I went to backup my computer to my external hard drive I accidentally told my mac to forget the hard drive and now it wont recognize hard drive.
MacBook Air 13″, macOS 11.2
Try a different cable, a different USB port, or both. If it still does not appear in Disk Utility, you might try starting your Mac in macOS Recovery mode, and using its version of Disk Utility: How to repair a Mac disk with Disk Utility - Apple Support. All the way at the bottom of that document describes the three steps to follow If your disk doesn't appear in Disk Utility.
If you have or can borrow another Mac try that too. The idea is to isolate the problem to the Mac or the hard disk drive.
Try a different cable, a different USB port, or both. If it still does not appear in Disk Utility, you might try starting your Mac in macOS Recovery mode, and using its version of Disk Utility: How to repair a Mac disk with Disk Utility - Apple Support. All the way at the bottom of that document describes the three steps to follow If your disk doesn't appear in Disk Utility.
If you have or can borrow another Mac try that too. The idea is to isolate the problem to the Mac or the hard disk drive.
Open Time Machine Preferences and click the Select Backup Disk... button.
It's ok to remove a disk from Time Machine. I'm assuming that's what you did, but whatever happened, that action should not have caused any permanent loss of anything. You ought to be able to simply add it to Time Machine again.
Does it appear in Disk Utility? Disk Utility User Guide for Mac - Apple Support
When I do that, it is not listed anymore. The only option is "Other AirPort Time Capsule"
it does not appear on disk utility.
I accidentally selected "remove the disc" but still want to be able to backup to that disc. How can I get it to show up again?
