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How to allow users to download exe-files

(Kristofer Gafvert, July 19, 2005)

When IIS 6.0 was introduced, it seems that it has become a common problem how to allow users to download exe-files (and execute the files on the client). By default, IIS 6.0 will not serve unknown extensions[1] and this includes exe-files. When a user requests such file, IIS will reply back with a 404 status code. A look in the IIS log file will show that the substatus code (sc-substatus) is 3 (the complete status code will be 404.3), which means that the MIME map policy prevented the request.

The solution to this problem is to allow the exe extension. The solution is the exact same as in IIS 5.0 and IIS 5.1, but since those IIS versions was not locked down by default, there were never a need to apply the solution (because it was already working).

To allow exe-files to be downloaded to the client, follow these steps:

  • Open IIS Manager[2].
  • Right click the folder where the exe-files are located and click Properties.
  • Click the "HTTP Headers" tab
  • Click on the "MIME Types" button
  • Click New
  • In the extension box, type .exe
  • In the MIME Type box, type application/octet-stream
  • Apply the new settings

Applies to [?]

IIS 6.0


[1] KB 326965, IIS 6.0 Does Not Serve Unknown MIME Types
[2] What is IIS Manager?