iTunes issues

Hi this is my first post to a forum and I hope that I have understood the rules.
I recently updated iTunes to 11.1 and found that the installer wouldn't install and I got error messages.
Having battled with trying to re- install iTunes after uninstalling it and attempting a clean install, I have gotten nowhere. I have spent weeks on this and am finally at the point of despair.

The error I seem to get is the following: Error writing to file. C:\ProgramData\188F1432-103A-4ffb-80F1-36B633C5C9E1\x86\DIFxAPI.dll. Verify that you have access to that directory.


I have tried to slim down the installation and only install iTunes.msi, yet I still get the same error message. I have used Dll file fixer and a registry repair. each of these reports that there are no errors or fixes the few it finds. I run the installation again and it fails.


I have a Dell XPS 710 with Windows 7 installed 32 bit.

I would appreciate some help to resolve this.
Thanks

 

Have tried uninstalling itunes and removing all existing files including the Apple software ??