如何在使用VS MSI Installer进行安装之前备份Web.config

I am using a regular Visual Studio Setup Project to deploy my ASP.NET application. I need to handle the case of an existing web.config existing in the target directory. When one is found, it needs to be renamed before the install takes place. If this does not happen, the new web.config will not overwrite the old. I am using a regular Visual Studio Setup Projec