It sounds like you are not able to open iTunes after a recent update was installed. I recommend the troubleshooting from the article named:
iTunes 11.1.4 for Windows: Unable to install or open
Check for .dll files
- Go to C:\Program Files (x86)\iTunes and C:\Program Files\iTunes and look for .dll files.
- If you find QTMovie.DLL, or any other .dll files, move them to the desktop.
- Reboot your computer.
Note: Depending on your operating system, you may only have one of the listed paths.
Uninstall and reinstall iTunes
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