You're mid-backup, and Windows throws 0XC0000174 – STATUS_DEVICE_NOT_PARTITIONED. The tape drive shows up in Device Manager, but when you try to load a tape or run a backup job, the OS says it can't find the partition information. This usually happens right after you insert a new tape, or when you rotate in an old tape that's been sitting on a shelf for months. It also crops up after a power failure or a hard system crash while a tape was loaded.
What's actually happening
The tape drive speaks SCSI or SAS, and Windows asks it for the tape's partition table—essentially, how the tape is laid out into partitions. Your drive responds with garbage or nothing at all. That's the 0XC0000174 error. The drive is physically there, but it can't interpret the tape's structure.
The culprit here is almost always one of three things:
- A dirty tape path. Over time, tape residue and dust build up on the read/write heads. The drive can't read the servo tracks or the partition info reliably.
- Corrupt tape metadata. The tape's header block (which stores partition boundaries) got scrambled. This can happen if the tape was ejected mid-write, or if the drive lost power at the wrong moment.
- Firmware or driver mismatch. Your drive firmware is ancient, or the Windows driver is a generic one that doesn't know how to talk to your drive properly.
Don't bother with registry edits or event log deep dives—they won't help you here. This is a hardware-level issue, and the fix is to get the drive to see the tape correctly again.
Step-by-step fix
Step 1: Clean the drive
Grab a cleaning tape that matches your drive type (LTO-4, LTO-5, etc.). Run a cleaning cycle. The drive usually auto-detects the cleaning tape and runs for about 30 seconds. If it doesn't, check your drive's manual—some drives need a command to force cleaning.
After cleaning, try loading the problematic tape again. If it works, you're done. If not, move on.
Step 2: Re-initialize the tape
If cleaning doesn't cut it, the tape's partition info is likely toast. You'll need to re-initialize (or re-tension) the tape. This wipes the tape, so back up any data you need first—if you can read it at all.
Use your backup software's tape utility if it has one (like Backup Exec's 'Format Tape' or Windows' own 'Format' in the Tape Devices section). If not, use rtmount or a vendor tool—e.g., for HP LTO drives, use the HP Library & Tape Tools.
In a pinch, use the built-in Windows tool. Open an admin command prompt and run:
tapeutil /format X:
Replace X: with your tape drive's device letter (check Device Manager if unsure). This will take a while—a full LTO-5 tape can take over an hour. Be patient.
Step 3: Update firmware
If the tape still throws the error after a clean or re-init, the drive firmware is probably lagging. Go to your drive vendor's site (HP, IBM, Dell, Quantum—whatever you have) and grab the latest firmware. This is a common fix for compatibility issues with newer tape media.
Follow the vendor's flashing instructions. Usually it's a bootable USB or a Windows executable. Don't interrupt the process—you'll brick the drive if you reboot mid-flash.
Step 4: Check the driver and connection
Open Device Manager, find your tape drive, and view its properties. Under the Driver tab, click 'Update Driver' and let Windows search. If it finds nothing, right-click and 'Uninstall device', then scan for hardware changes to reinstall. Also check your HBA or SAS cable—loose connections cause weird errors like this.
If it still fails
Try a different tape. If that works, your original tape is corrupted beyond recovery—toss it. If a known-good tape also fails, you're looking at a failing drive head or a logic board issue. Time to call a data recovery lab or replace the drive. Don't waste more than an hour on this; if cleaning and re-init don't fix it, the drive is suspect.
One last thing—check that your tape drive is compatible with the tape type you're using. An LTO-4 drive won't read LTO-5 tape, and a cheap SCSI card might not support the drive's features. That'll throw this error every time.