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 QuickTime or 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.

If the issue persists and you have a 64-bit system try the for older video cards version which is a 64-bit installer for mostly 32-bit code, similar to all 64-bit versions of iTunes up to 12.1.

If you've tried the above without success then see the method in Install missing components. What component fails to install, and what error message does it give? See this post for steps to produce detailed logs of the installation which may reveal why iTunes won't install.

The ..\Program Files\iTunes and ..\Program Files\Common Files\Apple folders should each weigh in at under 200Mb so 10.1 Gb of cleanup sounds excessive. Have you thrown away your media and/or device backups in error?

tt2

Try http://go.microsoft.com/?linkid=9779673, a Windows 10 compatible version of the Microsoft Program Installer & Uninstaller Fix-It tool.

tt2

I guess you'll have to try the whole process over again.

tt2

tt2

Can the Microsoft tool I mentioned earlier force through the installation of AMDS?

tt2

To those who were unable to resolve this issue, please follow the steps suggested on this article.

Remove and reinstall iTunes and related software components for Windows Vista, Windows 7, or Windows 8 - Apple Support

Don't get confused if the article subject does not include Windows 10. This was created way back before when Vista was first launched but this is applicable to Windows Vista, Windows 7, Windows 8, Windows 8.1, and Windows 10 OS.

Please be reminded to read the article very clearly since the uninstallation of iTunes and its related components should be "in order". Failure to do so will lead to possible errors and/or issues.

I've just had a go with the FixIt here. I was hoping you could point it at an EXE or MSI file that you wanted to install but it seems not.

Try installing the AMDS MSI file with the steps in this post for steps to produce detailed logs of the installation which may reveal why it won't install. Look for words like failed or error.

tt2

I fixed my problem by installing the

Microsoft Visual C++ 2005 Service Pack 1 Redistributable Package MFC Security Update

https://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=26347

The error message i had was "An error occurred during installation of assembly 'Microsoft.VC80.CRT, type="win32", version="8.0.50727.6195", publicKeyToken="1fc8b3b9a1e18e3b", processorArchitrcture="amd64" ' "