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 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.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 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.Try the following in turn until iTunes opens/reopens normally:
