When you connect a new device to the computer, Windows look for the relevant drivers for the proper functioning of the device. However, many users have reported encountering the ‘iTunes is Waiting for Windows Update’ error when connecting their iPhone to a Windows PC. Also, since the app can be downloaded for free, both from the iTunes website and the Microsoft Store, users find it a convenient and cost-effective solution. Note that iTunes 12.6.3.6 is the minimum version required for devices running iOS 11.Most iPhone users generally have the iTunes app on their computer to access their music library, create backups, transfer data, amongst other features. Or see the iTunes installers section of the troubleshooting tip and reinstall the last version that worked correctly for you.Disable any non-Microsoft anti-virus software when reinstalling and run the installer as the administrator. See the second box in Troubleshooting issues with iTunes for Windows updates for detailed tear down and rebuild advice.Temporarily disable any non-Microsoft anti-virus and see if that has any impact on the behaviour.We can go into details later if the issue is limited to your own profile.

If the problem only exists in your profile it may be possible to delete some of the iTunes preference files which it would seem that iTunes may be choking on.

Try Fix unexpected quits or launch issues in iTunes for Windows - Apple Support and test the behaviour in a different user profile or with a different library.

Delete the iTunes shortcuts from the start menu, desktop, task bar, or similar, then repair iTunes from the programs and features control panel.

Try disconnecting your computer from the Internet before running iTunes.

Again doing this once may sometimes help.

Try holding ctrl+shift as you launch iTunes so it opens in safe-mode.

Some users were finding that with the 12.6.1.25 build, for example, they had to use this method every time and modified the shortcut accordingly.

Doing this once may fix certain launch issues.

Locate the shortcut for iTunes, right-click on it, and select Run as administrator.

Exit the BTTray.exe Bluetooth utility if installed.

Remove any SD card that might be in a card reader.

If iTunes is apparently installed correctly try the following in turn until iTunes opens/closes/reopens/connects to the store normally:

Itunes will not open windows 10