One suggestion is to use the value of the Installed_Version from the SilkTest registry hive.
 
The example below uses the registry path on a 64 bit machine:
 
         Dim myVal As String
            myVal = (My.Computer.Registry.GetValue("HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Borland\SilkTest", "Installed_Version", Nothing))
            MsgBox(myVal)




Location of Installed_Version in the SilkTest registry.