I\'m trying to find out how to read/write to the extended file properties in C# e.g. Comment, Bit Rate, Date Accessed, Category etc that you can see in Windows explorer. An
I'm not sure what types of files you are trying to write the properties for but taglib-sharp is an excellent open source tagging library that wraps up all this functionality nicely. It has a lot of built in support for most of the popular media file types but also allows you to do more advanced tagging with pretty much any file.
EDIT: I've updated the link to taglib sharp. The old link no longer worked.
EDIT: Updated the link once again per kzu's comment.