The silverlight dose not need any special server requirements. Silverlight websites can be run on very simple windows servers having dotnet framework, ms sql (If website need). All you need to add MIME types to support the correct content type interpretation by the browser. Generally in IIS7, these MIME types are already added. If they are not it will give errors such as 404.3 or may prompt to download etc.
There are 3 MIME types need to add.
Below are the steps to add MIME types into IIS6.
1. Open the IIS.
2. Right click on website / Domain Name.
3. Click on “Properties”.
4. Select the registrar “HTTP-Header”.
5. Select the register “HTTP-Header”
6. Click on the button “MIME Types”.
7. If .xaml is not listed as a type, Click on “New”
8. Enter the following description:
MIME type: application/xaml+xml
9. Click “Ok”,
10. Do the same for .xap and .xbap
11. Click on “Apply”
Original post you will get athttp://www.goonclick.com/server-requirements-for-silverlight/