I have purchased an ebook and need adobe reader 8.1.1 to be able to access my book. when i try to run adobe reader 8.1.1 it says
window installer: The upgrade patch cannot be installed by the windows installer service because the program to be upgraded may be missing, or the upgrade patch may update a diffrent version of the program. verify that the program to be upgraded exists on your computer and that you have the correct upgrade patch.
what do i need to do?