MS Compatibility Pack Content Types in Windows Registry

Hi,

I have a small program which opens a docx, pptx, and xlsx files in IE. However, the server does not display the filename (sampledoc.docx) in the link for security purposes. Thus, only sends the content type which IE uses to counter check the file type against Windows registry.

Currently, I have MS Office 2003 installed with updates and compatibility pack.

Issue: when openning these files from IE, its file type is still unknown.

Workaround: I have manually added content types with corresponding file extension in the registry.

Question: Who is responsible in adding the content types and file extensions in Windows registry? Does installing the MS compatibility pack the one to add these content types?

Hope someone knows the answer for this...

Regards,
Ruby