Hi,
I just tested upgrade of our app in Windows 7, install built with AI 7.5, and got an error message from Windows/MSI.
Log enclosed, the installation was done on a Norwegian locale. An english translation of the error message would be something like
"Another version of this product is already installed. Installation of this version can not proceed. If you would like to configure or remove the existing version of this product, use Add/Remove programs in Control panel"
Installation/upgrade in XP work as expected.
Could someone please have a look at this, and promote it to a bug report if necessary.
-frode