Setup Project For A Windows Service - Pre-Install Custom Action?

I need to install a windows service via an .msi for many tablets which is nooooo problem. The problem is, the tablets currently have the service running which was installed by installutil. So when my installer runs, regardless of Remove Previous Version is true, it stops stating the service already exists and to uninstall it from Add/Remove Programs.So I wrote a console app which preceeds the primary output as follows:

Sub Main()
Try
Dim filename As String = "C:Program FilesRSCProjectServiceSetupRSCProjectService.exe"
'Dim filename As String = "C:RSCProjectServiceRSCProjectServiceinDebugRSCProjectService.exe"
If System.IO.File.Exists(filename) Then

[code]....