Quick answer: Open %SystemRoot%\system32\ntmsmgr.msc, find the media in the Offline Media Libraries folder, right-click it, and select Online.
What's going on here
ERROR_MEDIA_OFFLINE (0X000010D0) hits when you're using Windows backup tools — usually NTBackup on older systems like Windows 2003/XP, or a third-party app that calls the Removable Storage Manager API. The error message says it all: the tape, magneto-optical disc, or other removable media you're trying to use is currently in an offline library. Think of it like a book sitting in a closed library annex — you can't check it out until the annex opens.
This happens most often after you've moved a tape from one library to another, rebooted the server with a tape still in the drive, or swapped out a library without properly ejecting media. The Removable Storage Manager keeps a list of all media and their online/offline status. Sometimes that status gets out of sync with reality.
Here's the deal: the media itself might be physically fine. The slot it's in might be fine. But the software thinks it's offline, so it won't let you read or write to it until you flip that status back.
Step-by-step fix
- Open Removable Storage Manager. Click Start, type
ntmsmgr.mscin the Run box (or search bar on newer Windows), and press Enter. You'll see the Removable Storage snap-in open up. - In the left pane, expand Libraries. You'll see a list of all the tape and disc libraries the system knows about. If you're using a standalone tape drive, it'll show under a library named something like "Tape Drive 0".
- Inside each library, you'll see Media and sometimes Offline Media. Click Offline Media. This folder shows every piece of media that the Removable Storage Manager thinks is offline. After clicking it, the right pane should list the media by barcode or label.
- Find the media that matches the error. Look for the barcode or label you're trying to use. If you're not sure which one it is, check the error details in your backup software — it often includes the media ID.
- Right-click that media and select Online. A dialog might pop up asking you to confirm. Click Yes. After you do this, the media should disappear from the Offline Media folder and appear under the normal Media folder inside the library.
- Close the Removable Storage snap-in and try your backup or restore operation again. It should now see the media as available.
That's the main fix. About 80% of the time, this is all you need.
Alternative fixes if that didn't work
Check the physical connection
If the media won't go online, the tape drive or library might actually be disconnected or powered off. Check the SCSI/FC cables, the power cable, and the drive's front panel for any error lights. For tape autoloaders with multiple slots, make sure the library is powered on and initialized — some need a minute after power-up to scan the slots.
Restart the Removable Storage service
The service behind this whole thing is Removable Storage. If it's hung or corrupted, media stays offline no matter what you click. Here's how to restart it:
- Open a command prompt as Administrator — right-click Command Prompt and pick Run as administrator.
- Type
net stop rsmand press Enter. Wait 10 seconds. - Type
net start rsmand press Enter. - Close the command prompt and try the ntmsmgr.msc steps again.
Manually set the media online via VBScript
If the GUI is being stubborn — maybe the media shows up but the right-click menu is grayed out — you can force it with a script. Save this as a .vbs file and run it:
Set objRS = CreateObject("RasShell.RemoteStorage")
objRS.Online "Tape0"
Replace "Tape0" with the actual media ID you see in the Offline Media list. You can find the ID by looking at the Name column in the snap-in. Run the script, and it should bring the media online without any dialogs.
Use the Backup Exec or NetBackup console
If you're running a third-party backup tool like Veritas Backup Exec or Symantec NetBackup, those apps have their own media management. Sometimes the Windows Removable Storage Manager shows the media as offline because the backup app has exclusive control. Open your backup software's console, go to the media management section, and look for an option to "import" or "inventory" the tape. That operation usually syncs the media state with Windows.
Prevention tip
This error comes back if you frequently swap tapes between libraries or drives. The easiest way to avoid it: always eject media through the backup software before physically removing it. If you yank a tape while the drive is still talking to it, the Removable Storage Manager marks it offline next time you insert it. Also, if you're running Windows Server 2003 or 2008, consider migrating away from the old Removable Storage Manager — Windows Server Backup doesn't use it, and modern backup apps like Veeam manage their own media state without touching RSM at all.