This means the IPSW firmware file could not be accessed during the restore, usually because it was moved, locked, or blocked by another program while iTunes was preparing it. Jump to your situation below or work through the methods in order.
By Neeraj Singh ~6 min Updated Jun 2026 86% found this helpful
Error message
The iPhone could not be restored. An unknown error occurred (1644).
Summary
iPhone restore error 1644 means the IPSW firmware file could not be accessed when iTunes or Finder needed it during the restore. Apple lists it among the errors caused by USB connection or security-software interference, and in practice it appears when the IPSW is moved, renamed, or deleted mid-process, or when antivirus or another program locks the file while the tool is reading it. The fix is to leave the IPSW file completely untouched in its folder until the restore finishes, keep a local copy (not on a network share or removable drive that could drop out), re-download a fresh IPSW if the current one may be corrupt or altered, and disable interfering security software during the restore. Restarting iTunes or Finder and retrying with the file left alone usually completes it.
What this error means
During a restore, iTunes or Finder reads the IPSW firmware file repeatedly as it prepares and writes it. Error 1644 means that read failed, the file it expected was not where it left it, or it was locked by something else at the moment it needed it.
That usually happens because the file was moved or renamed mid-process, or because antivirus or another program grabbed a lock on it. Leaving the file untouched, keeping it local, and stopping software from interfering lets the tool read it cleanly from start to finish.
Common causes
The IPSW file was moved, renamed, or deleted during the restore.
Antivirus or another program locked the file.
The IPSW is corrupt or was altered.
The file is on a network or removable drive that dropped out.
Security software interfered with the read.
Expert insight
“1644 is iTunes reaching for the IPSW and finding it gone or locked. The classic mistake is moving or renaming the firmware file while the restore is running, so rule one is leave the file completely alone until it finishes. The other culprit is antivirus grabbing a lock on it mid-read, so I pause that for the restore. Keep the IPSW on a local drive, not a network share or USB stick that can drop, and if there is any doubt about the file, re-download a fresh one.”
Manager, Tech Support & Operations · 19+ years fixing Windows and system errors
✓ How to fix it
Method 1
Leave the IPSW file untouched
1Do not move, rename, or delete the IPSW file while the restore is running.
2Let iTunes or Finder finish with it first.
3Retry with the file left in place.
Method 2
Disable interfering security software
1Temporarily disable antivirus or any tool that may lock the file during the restore.
2Add iTunes or Finder as an exception if you prefer.
3Re-enable protection afterwards.
Method 3
Re-download a fresh IPSW
1If the firmware may be corrupt or altered, download a fresh, signed IPSW.
2Point iTunes at the new file, or let it download the firmware itself.
3Then restore.
Method 4
Keep the IPSW on a local drive
1Store the IPSW on a local internal drive, not a network share or removable drive that can disconnect.
2This keeps it available throughout.
3Retry from the local copy.
Method 5
Restart iTunes and retry
1Close and reopen iTunes or Finder, then start the restore again.
2A fresh session clears a stale file handle.
3Leave the file alone as it runs.
1644 means iTunes could not access the IPSW file during the restore, because it was moved, locked, or blocked. Leave the file completely untouched until the restore finishes, keep it on a local drive, disable interfering security software, and re-download a fresh IPSW if it may be corrupt. Restart the tool and retry.
Frequently asked questions
What does iPhone error 1644 mean?
It means iTunes or Finder could not access the IPSW firmware file during the restore, usually because it was moved, renamed, or deleted mid-process, or locked by antivirus or another program.
How do I fix it?
Leave the IPSW file completely untouched until the restore finishes, keep it on a local drive, disable interfering security software, and re-download a fresh IPSW if it may be corrupt, then retry.
Why should I not touch the file?
iTunes or Finder reads the IPSW repeatedly during the restore. Moving, renaming, or deleting it mid-process means the tool cannot find it when it needs it, which triggers 1644.
Could antivirus cause 1644?
Yes. Antivirus or another program can lock the IPSW file while iTunes is reading it, blocking access. Temporarily disable it or add iTunes as an exception during the restore.
Should the IPSW be on a local drive?
Yes. Keep it on a local internal drive rather than a network share or removable drive, which can disconnect mid-restore and leave the file unavailable, causing the error.
What if the IPSW is corrupt?
Re-download a fresh, signed IPSW, or let iTunes or Finder download the firmware itself. A corrupt or altered file can also cause 1644, so a clean copy resolves it.
Still not working?
If 1644 continues with a fresh local IPSW and security software off, the drive holding the file or the temporary folder may have permission or space problems; restoring with the IPSW in a simple local folder such as the desktop isolates that. You can also submit your error to us for a tailored fix.
