Hard drive write protected puzzle

Hi
I did a copy backup to a nas. For whatever reason the source hdd became write protected on both partitions. I have added registry key to block it, run the disk part remove read only, still it remains write protected. I swapped in a new drive and put the source drive into an enclosure, it ran normally until it rebooted, when it became write protected again. Reboot, its ok, then not.... What is preventing resetting read only and why is it following it one minute and not the next?


andy

Here is co-pilot's answer and it stands to reason it is your issue. Hope it helps.

The behavior you’re seeing isn’t a Windows write‑protection flag. When a drive suddenly becomes read‑only, refuses to clear with diskpart, and only works on certain reboots, that’s almost always the HDD’s firmware forcing a protective read‑only mode due to hardware failure.

Your description — both partitions locking after the NAS copy, the attribute returning immediately, and the enclosure only working until the next reboot — fits a drive that’s tripping SMART or controller‑level errors. Once the drive warms up or hits a bad area, the firmware re‑evaluates its health and disables writes again.

Common triggers:

• SMART panic conditions (pending/reallocated sectors, write‑error spikes)
• Controller board instability
• USB‑SATA bridge reacting to repeated write failures
• Drive setting its own internal RO flag to protect data

Windows can’t override any of these, which is why the read‑only state keeps coming back.

Next steps:

1. Pull SMART data immediately.
2. Clone the drive while it still intermittently works (ddrescue recommended).
3. Retire the drive — this is end‑of‑life behavior

What to do next:

1. Stop trying to clear the write protection. It’s not a Windows setting — it’s a hardware safeguard.
2. Pull a SMART report immediately (CrystalDiskInfo or smartctl). Look for reallocated/pending sectors or write‑error spikes.
3. Clone the drive while it still intermittently allows writes. Use a tool that handles bad sectors gracefully (e.g., ddrescue).
4. Retire the drive. This is end‑of‑life behavior.