IIS 7.5 Compression creates compressed file but returns the non-compressed one

Question

I have trouble setting up the compressing in IIS 7.5. In the "%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files" folder there are my files gzipped, but the browser recieves the original files. Even after refreshing the page again and again with Ctrl + F5. Also, I tested this in Chrome, FF and IE (no "Content-Encoding: gzip"-header). The browser is sending the "Accept-Encoding:gzip, deflate, sdch"-header. Can someone give me a hint?

Here is what i've done so far:

1) Changed the appicationHost.config

<section name="httpCompression" allowDefinition="MachineToApplication" overrideModeDefault="Allow" />

2) Executed the following command in cmd

C:\Windows\System32\inetsrv\appcmd.exe unlock config /section:system.webServer/serverRuntime

3) Added the following to the web.config

<system.webServer>
  <serverRuntime frequentHitThreshold="1" frequentHitTimePeriod="10:00:00" />
  <httpCompression> 
    <staticTypes> 
      <add mimeType="text/*" enabled="true" /> 
      <add mimeType="message/*" enabled="true" /> 
      <add mimeType="application/javascript" enabled="true" /> 
      <add mimeType="application/x-javascript" enabled="true" /> 
      <add mimeType="image/jpeg" enabled="true" /> 
      <add mimeType="*/*" enabled="false" /> 
    </staticTypes> 
      <dynamicTypes> 
      <add mimeType="text/*" enabled="true" /> 
      <add mimeType="message/*" enabled="true" /> 
      <add mimeType="application/javascript" enabled="true" /> 
      <add mimeType="application/x-javascript" enabled="true" /> 
      <add mimeType="image/jpeg" enabled="true" /> 
      <add mimeType="*/*" enabled="false" /> 
    </dynamicTypes> 
    <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll" dynamicCompressionLevel="4" /> 
  </httpCompression>
</system.webServer>

4) Added the static- and dynamic-compression features in the Performance-Features in the Windows-Feature-Installer (hope this is called so)

5) Enabled the compression of static and dynamic content on the server-level. And disabled the "min-file-size"-setting.

6) Enabled the compression of static and dynamic content on the site-level.

Edit 1: Added the full headers.

Request Headers

Accept:*/*
Accept-Encoding:gzip, deflate, sdch
Accept-Language:de-DE,de;q=0.8,en-US;q=0.6,en;q=0.4
Cache-Control:no-cache
Connection:keep-alive
Host:web.web
Pragma:no-cache
Referer:http://web.web/
User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.115 Safari/537.36

Response Headers

Accept-Ranges:bytes
Content-Length:385105
Content-Type:application/x-javascript
Date:Tue, 03 Mar 2015 14:09:48 GMT
ETag:"0535c4b155d01:0"
Last-Modified:Tue, 03 Mar 2015 12:58:38 GMT
Server:Microsoft-IIS/7.5
Vary:Accept-Encoding
X-Powered-By:ASP.NET

Ushas

where did you add the headers and why is that important? I've done everything you have and still get the uncompressed files. I've switched off Eset Anti Virus too, no joy. – Schweiker

Answer 1

I found the source of my problem.

I disabled Kaspersky AntiVirus and everything worked exactly as expected.

I do not know why this has impact on this exactly, but maybe this helps someone someday.

Edit 1

On a server with the server-version of Kaspersky everything works as expected.

Ushas