Determining if the dotnet framework is on a client pc

Encountered the issue of needing to know if a client had the dotnet framework installed on his machine or not. Below is the VB6 code of the utility i wrote in order to determine this...

UI controls:

Control type                  Name:
Button                          Command1
Label                           lblFx1
Label                           lblFx2


Code:

Private Sub Command1_Click()
   Unload Me
End Sub

Private Sub Form_Load()
   If DoesFileExist(Environ$("windir") & "\Microsoft.NET\Framework\v1.0.3705\mscorlib.dll") Then
      lblFx1 = "Framework 1.0 is installed"
   Else
      lblFx1 = "Framework 1.0 is NOT installed"
   End If

   If DoesFileExist(Environ$("windir") & "\Microsoft.NET\Framework\v1.1.4322\mscorlib.dll") Then
      lblFx2 = "Framework 1.1 is installed"
   Else
      lblFx2 = "Framework 1.1 is NOT installed"
   End If

End Sub

Private Function DoesFileExist(FN As String) As Boolean
On Error GoTo errh

   Dim a
   DoesFileExist = True
   a = GetAttr(FN)

   Exit Function
errh:
   DoesFileExist = False
End Function