Where is my iTunes Setup file?

There is some anecdotal evidence that the scripts on the Apple site that are supposed to detect the version of Windows you are running may fail for some users - jumping straight to the "Thank you for downloading ..." page with the installer not having been downloaded. As an alternative, you can go directly to the relevant downloads - like the previous 12.1.0.77 release, there are three different installers available, with direct links to these as follows:

• iTunes 12.1.1.4 (32-bit) - iTunesSetup.exe
• iTunes 12.1.1.4 (64-bit) - itunes6464setup.exe
• iTunes 12.1.1.4 (64-bit "for older video cards") - iTunes64Setup.exe

The third of these - which is actually the 32-bit application with a 64-bit installer - should be used if you get a warning about video card incompatibility when you install the standard 64-bit version. Based on evidence of the previous release, this may also be an appropriate alternative if you have playback issues or crashes with the standard 64-bit version. In the case of playback issues, you should check the following before trying the "for older video cards" version:

• Varying the Play Audio Using settings under Edit > Preferences > Playback (you need to restart iTunes for changes to take effect). Setting this to "Direct Sound" rather than "Windows Audio Session" has been reported to address some playback issues (though some users have stated the reverse to be the case - this may vary with specific audio hardware/drivers)
• Verify that you have the latest version (7.7.6) of QuickTime installed - some users have found that absence of QuickTime, or an out-of-date version can result in complete lack of audio output, particularly (though not exclusively) with Bluetooth audio devices.

See turingtest2's notes on Troubleshooting issues with iTunes for Windows updates for more details if you're still having problems with installation.