Iis404 does not have a MIME suffix set

Earlier versions of IIS contain wildcard MIME mappings that allow IIS to process any file without having to consider the extension. IIS 6.0 does not contain the wildcard MIME mapping and cannot handle extensions of any type that are defined outside of the MimeMap node in the IIS metabase.
Solution:
To define a MIME type for a specific extension, follow these steps:
1. Open the IIS Microsoft management Console
(MMC), right-click the local computer name, and then click Properties.
2. Click MIME Type.
3. Click "New".
4. In the Extension box, type the file name extension you want (for example,. pdb).
5. In the MIME type box, type Application/octet-stream.
6. Apply the new settings. Note that you must restart the World Wide Web Publishing Service or wait for the worker process to cycle for the changes to take effect. In this example, IIS can now process files with a. pdb extension. If you want to work with all files regardless of the file name extension (for example, if you cannot predict all files that will be processed), follow these steps to add a wildcard mapping:
Note: You can only add a wildcard map to the IIS MIME map during troubleshooting as a temporary solution. After you determine that the missing MIME type is the cause of the problem, remove the wildcard mapping, and then add a specific mapping of the MIME types that you want to handle.
1. Open the IIS Microsoft management Console
(MMC), right-click the local computer name, and then click Properties.
2. Click MIME Type.
3. Click "New".
4. In the Extension box, type an asterisk (*).
5. In the MIME type box, type Application/octet-stream.
6. Apply the new settings. You must restart the World Wide Web Publishing Service or wait for the worker process to cycle for the changes to take effect.

Iis404 does not have a MIME suffix set