---
id: external-drives.transfer-drive-says-already-a-storage-studio-drive
url: https://storagestudio.us/faq/external-drives/transfer-drive-says-already-a-storage-studio-drive
category: "External drives"
subcategory: "Upgrading, transferring and backing up the drive"
question: "Why won't Transfer Drive use a drive that is already a Storage Studio drive?"
alt_questions:
  - "Already a Storage Studio drive for this Mac"
  - "Transfer back to my old fast drive"
  - "Can't transfer to previously used drive"
  - "transfer drive blocked already prepared"
  - "Use my old Storage Studio drive again"
  - "Destination drive already set up"
short_answer: "To keep your records from getting mixed up, Transfer and Backup Drive refuse a drive already set up for this Mac. If you no longer need what's on it, erase it in Disk Utility first, or pick another drive."
tags: ["transfer drive", "backup drive", "requirements"]
related: ["https://storagestudio.us/faq/external-drives/transfer-drive-vs-backup-drive", "https://storagestudio.us/faq/external-drives/what-checks-run-before-transfer-drive-starts", "https://storagestudio.us/faq/external-drives/how-do-i-move-everything-to-a-new-external-drive"]
applies_to: "all"
last_reviewed: 2026-10-01
---

# Why won't Transfer Drive use a drive that is already a Storage Studio drive?

Transfer Drive and Backup Drive won't copy onto a drive that's already set up as a Storage Studio drive for this Mac, so two copies of your records can never get mixed up on one disk.

If you want to reuse such a drive — for example an old drive you transferred away from — first make sure you no longer need anything on it, then erase it in Disk Utility and pick it again. Or simply choose a different drive.