There are many reasons that your iTunes not working, such as old version, software crash, etc. You can follow some tips below to fix iTunes not working issue:
1. Update your iTunes to the latest version. You can download from Windows Store or iTunes official page.
2. Force quit iTunes. Go to task manager on your computer, and then right-click and choose End Task to force quit iTunes.
3. Run iTunes in safe mode. Press CTRL+SHIFT and then open iTunes. Click Continue to run iTunes in safe mode.
4. Restart your computer.
5. Repair iTunes. Find iTunes in App & features window. Then, click Modify and choose Repair in the pop-up window.
6. Use iTunes alternative. iTunes is actually not friendly at all, you can try to use some other third-party software to replace iTunes. In this post, there are some best iTunes alternatives for your iDevices: 10 Best iTunes Alternatives