How to Fix “iTunes Has an Invalid Signature” Error on Windows

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If you’re trying to update iTunes or your iPhone through iTunes on Windows and get hit with the error “iTunes has an invalid signature,” it usually means Windows can’t verify the update’s digital signature. This prevents iTunes from downloading or updating properly. Fortunately, there are a few effective ways to fix this.

1. Repair Apple Software Update

The Apple Software Update tool manages updates for iTunes and other Apple programs. If it’s corrupted, it can trigger the invalid signature error.

Here’s how to repair it:

  1. Press Windows + R to open Run.
  2. Type appwiz.cpl and hit Enter.
  3. Find Apple Software Update in the list.
  4. Right-click on it and choose Repair.
  5. Wait for Windows to finish repairing it.
  6. Restart your computer and try updating iTunes again.

2. Change Security Settings (Temporarily)

Sometimes, Windows blocks updates due to signature validation issues. You can allow unsigned updates — but only do this temporarily, as it can expose your system to risks.

To change the setting:

  1. Press Windows + R, type inetcpl.cpl, and press Enter.
  2. Click the Advanced tab.
  3. Scroll down to the Security section.
  4. Check the box next to:
    ✅ Allow software to run or install even if the signature is invalid
  5. Click Apply, then OK.
  6. Restart your PC and try updating iTunes again.

Important: Don’t forget to uncheck this option after the update to keep your system secure.

3. Manually Uninstall and Reinstall iTunes

If all else fails, doing a clean reinstall of iTunes can fix deeper software conflicts.

Step-by-step:

A. Uninstall all Apple components

  1. Press Windows + R, type appwiz.cpl, and hit Enter.
  2. Uninstall the following in this exact order:
    • iTunes
    • Apple Software Update
    • Apple Mobile Device Support
    • Bonjour
    • Apple Application Support (32-bit & 64-bit)

B. Delete leftover files

  1. Press Windows + R, type %programfiles%, and press Enter.
  2. Delete any of these folders if you see them:
    • iTunes
    • Bonjour
    • iPod
  3. Now go to Common Files > Apple and delete:
    • Mobile Device Support
    • Apple Application Support
    • CoreFP

On 64-bit systems, repeat the same steps inside the Program Files (x86) folder.

  1. Empty the Recycle Bin to remove everything completely.

C. Reinstall the latest version of iTunes

  1. Go to the official iTunes download page.
  2. Download the version for your Windows system (32-bit or 64-bit).
  3. Right-click the installer and choose Run as administrator.
  4. Follow the prompts to finish installation.

Once installed, try updating or syncing your iPhone through iTunes again — the signature error should now be gone.

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