Q: itunes install ?

Turingtest2's excellent iTunes for Windows Troubleshooting Guide at:

Troubleshooting issues with iTunes for Windows updates

may help with this issue.  The general troubleshooting advice when iTunes fails to install properly (and reinstalling or repairing it does not work) is to remove not only iTunes but all related components, reboot, remove the target installation folders and reinstall.  See the Removing and reinstalling iTunes and other software components section.

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

Use the links supplied above if that hasn't fixed it.

tt2

Unfortunately turingtest2's long list didn't help me. But running "Microsoft Installer Cleanup utility" against the "Apple Software Update" did!!   http://www.neowin.net/forum/topic/1277872-itunes-install-there-is-a-problem-with -this-windows-installer-package/