I thought all along it was an ini file problem. None of the folders/directors will let me change the attributes from read only to not read only.
So you couldn't try or test out what I posted then.
You are running the installer as Administrator, Media Center Edition must be different.
If you do have admin rights you probably have to go under the advanced file security settings. I think Media Center Edition does have security things because it can also be used as a server, probably more protection. What your describing sounds more like Vista with it's file protection.
Either way, if you can't change the files attributes then the installation program can't either.
Your only help is you or tech support.
I would still look into resetting the read-only flag on these directories & files. I've had some problems saving things in VS11+ and it was because the files were marked read-only in my users directory. After resetting them to normal then the program worked correctly.