Troubleshooting issues with iTunes for Windows updates

Last Modified: Jan 14, 2016 7:10 AM


The aim of this user tip is to provide iTunes removal and repair steps along with related advice all in one place, and to help avoid a complete reinstallation where it is not necessary. The key steps are in various boxes below. Some may not apply to your computer, but if they do you may save yourself some work over the full removal and reinstallation instructions given in the second box. Scroll down or click the further information link for additional help with installing or fixing any post-install problems, or review the list of support documents at the end in case one of them may help you.









iTunes launch errors caused by QTMovieWin.dll

Open the folder C:\Program Files\iTunes (32-bit systems) or C:\Program Files (x86)\iTunes (64-bit systems).


Check for a file with the name QTMovieWin.dll in the above locations only - if found delete it.


Start iTunes. If it runs normally there is no need to repair your iTunes installation at this stage.

Applies to errors such as:

  • Entry point not found: videoTracks@QTMovie@@QBE?AV?$Vector@V?$RefPtr@VQTTrack@@@***@@$0A@VCrashOnOverf low@@***@@XZ could not be located in the dynamic link library C:\Program Files(x86)\Common Files\Apple\Apple Application Support\WebKit.dll
  • The procedure entry point ?fastFree@***@@YAXPAX@Z could not be located in the dynamic link library JavaScriptCore.dll



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The general troubleshooting advice when iTunes fails to install properly (and reinstalling or repairing it does not work) is to remove not only iTunes but all related components, reboot, remove the target installation folders and reinstall.




Removing and reinstalling iTunes and other software components


If applicable, disconnect any iPod or iOS device and close Microsoft Outlook.


Go to Control Panel > Add or Remove Programs (Win XP) or Programs and Features (later).


Remove all of these items in the following order:

  • iTunes
(see note 1 below)
  • Apple Software Update
(if this will not uninstall try repairing it first)
  • Apple Mobile Device Support
(see note 1)
  • iCloud                  (if present)
  • MobileMe             (if present)
(see note 2)
  • Bonjour
(see note 1)
  • Apple Application Support
(see note 1)


Reboot your computer.


Delete any of the following folders where they can be found:      (see note 3)

  • C:\Program Files\Bonjour
  • C:\Program Files\Common Files\Apple
  • C:\Program Files\iPod
  • C:\Program Files\iTunes

also on 64-bit systems:

  • C:\Program Files (x86)\Bonjour
  • C:\Program Files (x86)\Common Files\Apple
  • C:\Program Files (x86)\iPod
  • C:\Program Files (x86)\iTunes

and where C:\ may need to replaced with the drive letter of your system drive if different.


Download the iTunes setup file and run it to install. Use an account with administrative rights. This can usually be achieved by right-clicking on the downloaded file and selecting Run as... or Run as administrator. In some cases a combination of Shift or Ctrl keys may be required for the option to show, or it may not be necessary.


If you deleted the iCloud Control Panel and reinstalling iTunes doesn't automatically reinstall it visit HT204283: Download iCloud for Windows (7 or later). iCloud support for Windows Vista has been dropped. See DL1687: Cloud Control Panel 2.1.3 for Windows Vista for an archived version of the relevant support document. There is no available download.

Some users may need to go through the above process more than once before it is successful.



Note 1

Some users may find that a particular component such as Apple Mobile Device Support or Apple Application Support will not uninstall or generates a missing .msi error. In such cases try the section Missing MSI errors below, or continue to remove the components that will uninstall, then proceed to the named folder removals. Alternatively the Microsoft Program Install and Uninstall Utility (MS Installer "Fixit") may help with stubborn items (Windows 8.1 or lower) or use for a Windows 10 compatible version of the same tool. Third-party AirPrint support services may also prevent Bonjour from being removed. If so these should be uninstalled first. It may also help to temporarily disable anti-virus software and/or the Windows User Account Control feature (Turn UAC on/off) while repairing software. See also HT3960: iTunes for Windows: Background processes installed on Windows XP, Vista, and 7 (archive copy) for a list of processes that might need to be halted while attempting to uninstall components of iTunes.



Note 2

MobileMe is a discontinued service and the control panel should be removed if present. Not doing so could cause Microsoft Outlook to freeze and/or issue error messages. See HT2992: MobileMe: Uninstalling the MobileMe Control Panel for Windows for details (archive copy). The Microsoft Program Install and Uninstall Utility (MS Installer "Fixit") may be able to remove MobileMe if you cannot find an entry to uninstall.



Note 3

The utility Unlocker may be able to reveal which processes are preventing you from deleting folders and either close the locking handle or force delete the folder. Autoruns is another useful tool for identifying and selectively disabling start-up processes. You may also find that you can delete the files or folders in question if you reboot the computer into Safe Mode.



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iTunes launch errors caused by iAdCore.dll

Open the folder C:\Program Files\iTunes (32-bit systems) or C:\Program Files (x86)\iTunes (64-bit systems).


Check for a file with the name iAdCore.dll in the above locations only - if found delete it.


Windows Vista & later: Open the Programs and Features control panel, select iTunes and click Repair.

Windows XP: Open the Add or Remove Programs control panel, select iTunes, then Change... Repair.

Applies to errors such as:

  • The procedure entry point ADiAdID_AquireMatchSlotIfNecessary could not be located in the dynamic link library iAdCore.dll



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Install missing components

For reasons that are unclear the iTunes installer may fail to install or update specific components such as Apple Application Support or Apple Mobile Device Support, even when undertaking a "clean" install such as that described above in Removing and reinstalling iTunes and other software components. In such cases it may help to extract the individual components from the downloaded iTunesSetup.exe, itunes6464setup.exe or iTunes64Setup.exe file using a utility such as 7-Zip, then install the appropriate .msi file for the missing/outdated component.


Even when such components won't install the standalone installer may provide useful error messages that were suppressed during the initial attempt. You can also try removing everything once more then installing the individual .msi components in alphabetical order however the iCloud component should only be installed on Windows Vista. Windows 7 & 8 users should download that from HT204283: Download iCloud for Windows.

Applies to errors such as:

  • Apple Application Support was not found. Apple Application Support is required to run iTunesHelper. Please uninstall iTunes, then install iTunes again. Error 2



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Missing MSI errors

The following steps should remove the reference to a missing .msi file that the Windows Installer Service is trying to access while installing iTunes.


  1. Press WinLogoKey+R, type Regedit in the Run dialog and press Enter/Return.

  2. Click Edit > Find, type in the name of the problem .msi file, e.g. itunes6464.msi, change the Look at boxes so that only Data is ticked, then click Find Next. You should find it somewhere like:
    HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products\{Long string of letters & numbers}\SourceList

  3. Right-click on the immediate parent key with the long string of letters & numbers that contains the SourceList with the reference to the .msi file and click Export, save it to say the Desktop with the name iTunes.reg so the data can be restored if removing it doesn't help. Now right click on the key again and select Delete from the context menu. This should stop the Windows Installer from looking for the .msi when you reinstall iTunes.



If the install still won't go through then double click the iTunes.reg file you made to restore the data to the registry, then use the method shown at Install missing components to unpack the installer of your previous iTunes installation and extract the .msi file you require. Double-click this to attempt to uninstall the component. There are links to recent builds of iTunes in the iTunes installers section.

Applies to errors such as:

  • The feature you are trying to use is on a network resource that is unavailable.



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Further information:



If you have difficulty downloading the iTunes installer file try; unticking the "Keep me up to date..." box, clearing your browser's cache, changing pop-up blocker settings, right-clicking or ctrl-clicking the download button, using an alternate browser, or using these direct links:

  • iTunes for Windows (32-bit) (Windows 7 or later) - iTunesSetup.exe (2015-12-21)
  • iTunes for Windows (64-bit) (Windows 7 or later) - iTunes6464Setup.exe (2015-12-21)
  • iTunes for Windows (64-bit - for older video cards) (Windows 7 or later) - iTunes64Setup.exe (2015-12-21)

Windows XP or Vista users cannot install iTunes 12.2 or later and should install version from the iTunes installers section of this tip for iOS 9 support.



Use the last version above if, on a 64-bit version of Windows, you see the following alert when you start iTunes, or as a workaround if there are problems after installing iTunes6464Setup.exe such as crashes on launching iTunes, stuttering playback or loss of AirPlay. This last build is similar to releases of iTunes for 64-bit Windows prior to iTunes 12.1, being a 64-bit installer for the 32-bit core program. It may also be required if you need QuickTime support to add or play selected video content or have a 32-bit application that no longer integrates with iTunes..


See DL1816: iTunes 12.3 for Windows (64-bit - for older video cards) for more information.



The uninstall and reinstall process will preserve your iTunes library and any iOS device backups. You should check your preferences after reinstalling to make sure nothing has changed. Ideally you would backup the library and your other important personal documents and data on a regular basis. See the user tip Backup your iTunes for Windows library with SyncToy for a suggested strategy.



In the unlikely event that content is missing from the library following the reinstallation of iTunes, or you see the error message 'The file "iTunes Library.itl" cannot be read because it was created with a newer version of iTunes', see Empty/corrupt iTunes library after upgrade/crash.



If any of your original media has been deleted from your hard drive, and you don't have a back up, or if you need to change the computer you use to manage your devices, see Recover your iTunes library from your iPod or iOS device.



If an iTunes installation fails with the message "Error applying transforms. Verify that the specified transform paths are valid." this likely indicates that your language and regional preferences are not supported by the active iTunes installer. Temporarily changing to a supported language should allow the installation to complete. Supported languages should be: Arabic, Catalan, Chinese, Croatian, Czech, Danish, Dutch, English, Finnish, French, German, Greek, Hebrew, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Thai, Turkish, Ukrainian, and Vietnamese. This was an issue that affected Arabic and Portuguese (Portugal) users and the iTunes installer, but could potentially recur in another release.



Should you get "An internal error occurred" warning when reinstalling try creating a new user account with administrative rights and installing iTunes using that account. Alternatively try repairing and then removing Apple Software Update.



The message "An error occurred during installation of assembly 'Microsoft.VC80.CRT, type="win32", version="8.0.50727.6195", publicKeyToken="1fc8b3b9a1e18e3b", processorArchitrcture="amd64" ' " may occur because a particular library file is not included in the distribution package supplied with iTunes or won't install for some unspecified reason. Installing the Microsoft Visual C++ 2005 Service Pack 1 Redistributable Package MFC Security Update before attempting to reinstall iTunes may help.



For "Could not open key/write value" errors when reinstalling try b noir's user tip:

"Could not open key: UNKNOWN\Components\[LongStringOfLettersAndNumbers]\
[LongStringOfLettersAndNumbers]" error messages when installing iTunes for Windows

The technique can be applied to the branch of the registry mentioned in the error message.



For "Object already exists" or "Access denied" errors when installing try opening Control Panel > Programs and Features > View installed updates then checking for Security Update for Microsoft Windows (KB2918614). Uninstall if you have it, then reboot and try installing again.



For "Key not valid for use in specified state" errors try moving the folder RSA from C:\Users\<User>\AppData\Roaming\Microsoft\Crypto\RSA to say C:\RSA (just in case there should be a need to restore it) then try installing again. This folder appears to act as a cache and should be rebuilt automatically as required.



For "Invalid Drive" errors when uninstalling or reinstalling try b noir's user tip:

"Invalid drive X:\" install errors.



It may help to disable the real-time scanning component of any antivirus software during the reinstallation of iTunes.



If you followed Apple's guide and have a small collection of .dll files on your desktop these can be safely deleted.



Should you find that all of your desktop shortcuts have turned into links to the iTunes application download and apply the lnk registry fix from



For device connectivity issues see HT204095: iPhone, iPad, or iPod not recognized in iTunes for Windows and HT204089: iTunes 10.5 and later: Troubleshooting iTunes Wi-Fi syncing.



QuickTime: It is worth noting that iTunes no longer relies on QuickTime in the way that it used to. Unless you have some obscure file formats that still require QuickTime support you may prefer to remove this component from your system while uninstalling other items as part of the repair process. If it isn't removed it may need repairing from the control panel after you have reinstalled iTunes. Conversely, if you removed QuickTime and find that some older content no longer plays then try reinstalling QuickTime. You may also find that for QuickTime to work with iTunes you need to install the iTunes for Windows (64-bit - for older video cards) version.



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iTunes installers:



If you are unable to get the current version of iTunes to work on your computer you may wish to try reinstalling a previous build from the links below after going through the removal steps once more. In order to roll back to an older version of iTunes you may also need to restore the pre-upgrade library as described in Empty/corrupt iTunes library after upgrade/crash. Having rolled back to an older build on the first run it is likely to tell you there is a new version of iTunes, tick "Do not ask me again" and then click "Don't Download" to avoid reminders until you choose to upgrade again. Some users have also reported success with using System Restore to revert to a pre-upgrade snapshot of their system.


N.b. iTunes 12.2 and later versions require Windows 7 or later.

N.b. The 32-bit versions listed below require Windows XP SP3 or later, the 64-bit versions require Windows Vista or later.

See also for selected older versions of iTunes.



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Support documents:


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