Something I've noticed with these installs is that you don't want to mess with the indexes in SQL. All of the installers first confirm that the indexes exist, if they don't the install fails. We had some indexing work done to improve performance that we had to remove to run through an install. We found this out by a failed install.
Also, a prerequisite would be to have Full Text Search on. The Microsoft Search service is a requirement for the installs we went thr