Roland, we need a little more info in order to help you. First, if you used the quotes around C:\Pro Audio 9 that was my fault ... I should have told you without the quotes. If you did not use the quotes, then what happened as well as you can remember? Do you have Vista's User Account Control active on the computer? If so, you have to disable it while you are trying to install Pro Audio 9. In addition, you should run as administrator during the install. HTH