Q: older itunes app removal

Assuming that you are on a Windows PC:

1. Reboot
2. Temporarily disable your antivirus software
3. Use Programs and Features to uninstall iTunes
4. Download and install the latest iTunes only fro the official source (https://www.apple.com/itunes/download/)
5. Test iTunes
6. Re-enable your antivirus

If that fails to work, then try the following:

Remove and reinstall iTunes and related software components for Windows 7 and later - Apple Support

After removing yet before installing again, I would highly recommend using CCleaner to (https://www.piriform.com/ccleaner) clean your registry, then reboot prior to trying a reinstallation.  This will remove all old registry entries related to iTunes that may be giving you reinstallation problems.

Try repairing Apple Software Update from the programs & features control panel, and then try to update iTunes again.

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.

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