IO.File.Delete(path)

Dim f as new FileInfo(path)
if f.exist then
f.delete()    
end if

Imports System
Imports System.Runtime.InteropServices
Imports System.Security.Permissions
'The attribute is placed at the assembly level.
<assembly: PermissionSetAttribute(SecurityAction.RequestMinimum, Name := _
  "FullTrust")>
Namespace MyNamespace
   Public Class [MyClass]
      Public Sub New()
      End Sub
 
      Public Sub MyMethod()
         'Perform operations that require permissions here.
      End Sub 
   End Class
End Namespace