itunes won't run

reboot

and if that does not take care of it RBM on the iTunes shortcut and choose run as Administrator.

Try deleting any iTunes shortcut from the start menu, task bar or desktop, then repair iTunes from the programs and features control panel.

Otherwise for general advice see Troubleshooting issues with iTunes for Windows updates.

The steps in the second box are a guide to removing everything related to iTunes and then rebuilding it which is often a good starting point unless the symptoms indicate a more specific approach. When reinstalling right-click the downloaded installer and use run as administrator.

Review the other boxes and the list of support documents further down the page in case one of them applies.

The further information area has direct links to the current and recent builds in case you have problems downloading, need to revert to an older version or want to try the iTunes for Windows (64-bit - for older video cards) release as a workaround for installation or performance issues, or compatibility with third party software.

Your library and device backups should be unaffected by these steps but there are links to backup and recovery advice should it be needed.

tt2

Another thing to try if the twitter folks don't have the solution.

Fix unexpected quits or launch issues in iTunes for Windows - Apple Support.

Does the behavior persist in iTunes' own safe mode, or if you right-click the iTunes icon and use run as administrator, or in a different user profile?

tt2