hvorfor er exe filer ukendte type under download ?

Koden er:

Hvorfor bliver exe filer til ukendte typer af IE ?

---
<%
'--------------------------------------------
Response.Buffer = True
Dim strFilePath, strFileSize, strFileName

Const adTypeBinary = 1

strFilePath = "C:\inetpub\download\" & Request.QueryString("fil")

Response.Clear

Set objStream = Server.CreateObject("ADODB.Stream")
objStream.Open
objStream.Type = adTypeBinary
objStream.LoadFromFile strFilePath

strFileType = lcase(Right(strFileName, 4))

' Feel Free to Add Your Own Content-Types Here
Select Case strFileType
Case ".pdf"
ContentType = "application/pdf"
Case ".asf"
ContentType = "video/x-ms-asf"
Case ".avi"
ContentType = "video/avi"
Case ".doc"
ContentType = "application/msword"
Case ".zip"
ContentType = "application/zip"
Case ".xls"
ContentType = "application/vnd.ms-excel"
Case ".gif"
ContentType = "image/gif"
Case ".jpg", "jpeg"
ContentType = "image/jpeg"
Case ".wav"
ContentType = "audio/wav"
Case ".mp3"
ContentType = "audio/mpeg3"
Case ".mpg", "mpeg"
ContentType = "video/mpeg"
Case ".rtf"
ContentType = "application/rtf"
Case ".htm", "html"
ContentType = "text/html"
Case ".asp"
ContentType = "text/asp"
Case Else
'Handle All Other Files
ContentType = "application/octet-stream"
End Select


Response.AddHeader "Content-Disposition", "attachment; filename= strFileName"
Response.AddHeader "Content-Length", strFileSize
' In a Perfect World, Your Client would also have UTF-8 as the default
' In Their Browser
Response.Charset = "UTF-8"
Response.ContentType = ContentType

Response.BinaryWrite objStream.Read
Response.Flush

objStream.Close
Set objStream = Nothing
%>
---