Q: iTunes update for Windows 10 failure

Yeah, you have to actually remove almost everything Apple related installed from the Windows Programs and Features list as described in this article:Remove and reinstall iTunes and related software components for Windows 7 and later - Apple Support

If you cannot remove any one of the items, run a REPAIR against the software item and then try to remove it again.  Once I was able to remove all the items listed from the article I was finally able to install the latest iTunes.

Repair Apple Software Update from the programs & features control panel, and then try 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