title: Visual Studio Setup Project conditional if File Exists
body: <p>I have a Setup/Deployment Project for my Application and it outputs certain files (*.dll, *.dat) to the Application Folder.</p>
  
  <p>I would like a condition to be set to check if a file currently exists or not.  If it doesn't, write it but if it does, don't install it from the package.  Is it possible?</p>
  
  <p>The file is called "database.dat" and under the Properties, I see a "Condition" attribute, but I'm not familiar with what to put in there.</p>
  
  <p>Any input is greatly appreciated.  Thanks in advance.</p>
  
  <p>Edit:</p>
  
  <p>Reason why it would already exist is that from a previous install there would be data from a DataSet / Data Table which we don't want to overwrite.</p>