Fix 0x00000664: Windows Update Package Won't Open

Quick answer for pros

Delete the corrupt .msu file, re-download it directly from the Microsoft Update Catalog, and run DISM /Online /Cleanup-Image /RestoreHealth before installing.

What’s happening with error 0x00000664?

This error hits when you try to open an update package (like a .msu file from Windows Update Catalog) and Windows says it's invalid. In my years running a help desk blog, I saw this most often after a failed download — maybe your connection hiccuped, or the file got corrupted mid-transfer. The official name is ERROR_PATCH_PACKAGE_INVALID, and it's Windows protecting you from installing a broken update that could mess up your system. It can also appear if the package was signed for a different Windows version or architecture, like trying to install an x86 update on an x64 system.

I know this error is infuriating — especially when you're in the middle of patching a critical security flaw. But the fix is usually straightforward.

Fix steps

1. Delete the corrupt file. Locate the .msu file you downloaded (usually in Downloads folder) and delete it. Then empty your Recycle Bin.
2. Re-download from Microsoft Update Catalog. Go to catalog.update.microsoft.com. Search for the exact KB number you need (e.g., KB5034441). Make sure you pick the right version for your system — x64, x86, or ARM64. Check your system type in Settings > System > About.
3. Run DISM to prep your system. Before installing, open Command Prompt as Administrator. Run this command:

   DISM /Online /Cleanup-Image /RestoreHealth

   This fixes any component store corruption that might interfere with the update.
4. Now install the new download. Double-click the fresh .msu file. If it still fails, try installing via command line:

   wusa.exe C:\path\to\update.msu /quiet /norestart

   Replace the path with your actual file location.
5. Restart your PC. Even if it seems to succeed, a reboot finalizes the update.

If the fix doesn’t work

Sometimes the issue is deeper — your Windows Update components themselves are broken. Here’s my backup plan:

• Run the Windows Update Troubleshooter. Go to Settings > System > Troubleshoot > Other troubleshooters > Windows Update > Run. It’s basic but fixes common hiccups.
• Manual reset of Windows Update. Stop the services and clear the cache:

  net stop wuauserv
  net stop cryptSvc
  net stop bits
  net stop msiserver
  ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
  ren C:\Windows\System32\catroot2 catroot2.old
  net start wuauserv
  net start cryptSvc
  net start bits
  net start msiserver

  Then try the update again.
• Check for system file corruption. Run sfc /scannow in an admin Command Prompt. If it finds issues and can't fix them, the DISM command above usually finishes the job.

Real-world scenario: I had a client whose corporate proxy was stripping headers from .msu downloads. They got error 0x00000664 every time. Solution? Use the Microsoft Update Catalog directly from a non-proxied machine, download the file, and transfer via USB. Worked perfectly.

Prevention tip

Always verify the SHA-1 or SHA-256 hash of any .msu file after downloading. Microsoft publishes these hashes alongside each update in the Catalog. Compare them with a tool like certutil -hashfile filename.msu SHA256 in PowerShell. If they don't match, the file is corrupt — delete and re-download. I do this every time now after being burned by a corrupted KB update that blue-screened three machines in a row.

Also, avoid using third-party download managers for Windows updates — they can corrupt files. Stick to your browser’s built-in downloader or wget with SSL verification enabled.