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This article applies to Code42 for Enterprise version 4.

Other available versions:

Version 6 | Version 5icon.qnmark.png

Code42 Support

Adopt a computer with a different operating system or file system

This article applies to Code42 for Enterprise version 4.

Other available versions:

Version 6 | Version 5icon.qnmark.png


Are you changing your operating system or file system on your computer? Whether changing between Mac, Windows, Linux or even newer versions of the same operating system, adopting your existing backup can help you get started on your new system. By carefully following this tutorial, you can reconnect to the previous computer's backup archive, and avoid repeating the potentially lengthy initial backup.

If you are using Code42 for Enterprise version 3.4.1 or earlier, see Adopting A Computer With A Different Operating System (3.4.1 And Earlier) instead.


There are some special considerations when adopting a computer with a different operating system. This process assumes:

Not sure how to proceed?
If you have any questions about the steps outlined in this tutorial, please contact our Customer Champions for Code42 for Enterprise support before proceeding.

Step 1: Download and install CrashPlan

  1. Download and install the latest version of CrashPlan
  2. Sign in to your existing account

Step 2: Restore your files

Before you adopt a computer, it is important to replace all of the files you backed up previously onto the new computer. Any files you don't restore from your existing backup will be retained as deleted files and are less visible, which could lead to unintentional data loss. Additionally, if the previously backed up files are not restored to the computer before adopting it, you may have an extended wait to restore your files while CrashPlan synchronizes your device with the backup destination.

Before adopting, you can use any of the following methods to add your original files onto your new or re-built computer:

  • Restore files from the CrashPlan app.
  • Copy or transfer files from the old computer to the new computer. Some example methods:
    • Copy files with your operating system’s standard tools such as the Finder, Windows Explorer, cp command, or rsync command.
    • Restore files from a Time Machine backup.
    • Transfer files using Windows Easy Transfer.

Restore files to original location
To resume your previous backup as fast as possible, restore your files as described in our tutorial on restoring all files to a new computer or drive.

Step 3: Adopt your previous computer

Once your files have been restored to the new operating system, it's time to adopt your previous computer so that CrashPlan sees your new computer as a continuation of your previous computer. When you adopt, your new computer:

  • Is immediately linked to your existing backup settings, file selection, version history, and backup archive
  • Inherits your previous backup archive and attempts to resume backup

If the previously backed up files are not restored to the computer before adopting, you might have an extended wait to restore your data while CrashPlan synchronizes your computer with the backup destination. Any files that cannot be found during synchronization will be flagged as "missing" and you must follow these steps to restore them.

  1. In the Continue Backup message, click adopt
    I Don't See The Option To Adopt


  1. Select the computer you want to adopt
    If you're not sure which computer to adopt, see these adoption tips from our Customer Champions

    Adopt Options

  2. Enter your Email and Password again and click Sign In
    The Adoption Complete! message displays

After you adopt your previous computer, the CrashPlan app attempts to synchronize the folders included in your file selection with your backup archive. However, CrashPlan is looking for the file paths included in your file selection in their old location on your previous operating system. Since these paths don't exist on the new operating system, CrashPlan reports them as Missing.

Don't worry. As long as these folders remain in your file selection, they are safe in your backup archive. We'll walk through updating your file selection in the next step.

DO NOT deselect the folders from your old operating system! Deselecting files removes them from your backup archive and there is no way to recover them.

Adoption Missing Files

Note: The screenshots in this example show a Windows computer adopting a Mac computer.

Step 4: Update your file selection

Next, update the file selection to add the files and folders that you moved or restored to the new operating system. Once the adoption has completed and all previous settings have been applied, CrashPlan will report the old locations as "missing". By updating the file selection to include both the old locations and the new locations of your files (e.g., under a folder with a different user name), CrashPlan will de-duplicate the data.

In version 4.5 and later of the CrashPlan app, the default backup file selection is added to your backup file selection automatically after adopting a computer. You should verify that this update includes the folders you want backed up on your new computer.

Remember, DO NOT deselect the folders from your old operating system yet! Once these files are removed from your file selection, there is no way to restore them. Deselecting files removes them from your backup archive and there is no way to recover them.
  1. From Backup, click Change.
    Note that your previous computer's file selection displays under a hard drive icon with no label.
  2. Keep the previous folders selected. CrashPlan automatically removes any files that are deselected.
  3. Add folders from your new computer to your file selection.
Selecting Folders
If you are moving from a Mac or Linux device to a Windows device, select new folders to back up using the folder tree with the title of C:\ in the dialog. Do not make any additional selections in the folder tree that has no title, as this represents the Mac or Linux device you are moving from.

File Selection

  1. Click Save.

Step 5: Wait for CrashPlan to synchronize your file selection

After you add folders from your new operating system to your file selection, the CrashPlan app synchronizes your file selection. It detects the files you restored on your new computer, and recognizes them as the same files you previously backed up on your old computer. Any new files added to your selection are analyzed and prepared for backup.


Step 6: Clean up file selection (optional)

Use caution when changing your file selection
  • Always wait for backup progress to complete before deselecting files. The time needed to back up depends on data de-duplication and the size of your backup selection.
  • You should only deselect files that you want CrashPlan to permanently and immediately delete from your backup archive.
  • There is no way to recover deselected files.
  • You will lose any historical versions associated with the deselected folders and files. Even if the file verification scan has updated the new location information for your files, any versions associated with the old deselected location will be lost.

When backup progress completes, you may choose to clean up your file selection by removing the old "missing" locations of your files.

If you are not concerned with maintaining historical versions, and you want to clean up your file selection by removing the old file and folder paths, you must follow these steps exactly in the sequence presented:

  1. Verify that the new location for the files is included in your backup file selection.
  2. Keep the original file location selected. Do not deselect any files at this time.
  3. Allow your backup status to reach 100% complete.
  4. It is now safe to deselect the old files and folders. You can restore these files from their new location on your new computer.

When you change the backup file selection, a scan launches to compare the contents of your backup file selection against your existing backup archive. While on the surface it may look like CrashPlan is starting your backup over, this is a normal part of CrashPlan's operation. There are several ways to confirm that your backup isn't starting over.

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