Delete the folder:
C:\ProgramData\Apple\Lockdown
Reboot PC and try again.
Category Archives: iTunes
Can’t uninstall or update iTunes because of missing iTunes.msi
regedit
edit>find iTunes.msi or itunes64.msi
Delete the folder containing these keys.
Source: Apple Discussions
AppleSyncNotifier.exe – Entry Point Not Found
Copy:
libxml2.dll
SQLite3.dll
From: C:\Program Files\Common Files\Apple\Apple Application Support
To: C:\Program Files\Common Files\Apple\Mobile Device Support
Source: HowToGeek
“The Windows Installer Service could not be accessed” installing iTunes 64-bit Vista and Windows 7
Regedit
HKEY_LOCAL_MACHINE > System > CurrentControlSet > Services > MSIServer
Change WOW64 REG_DWORD value to 0
Source: Apple
Sign In To Use This Computer for Automatic Downloads
This alerts appears twice even though automatic downloads is disabled.
To fix:
iTunes/Preferences/Advanced/Reset Warnings.
Source: Apple