Read .doc or .rtf file using asp.net and C#

Question

How to read the .doc or .rtf file which is uploaded using file upload asp control and when submit it should display the content in Label using c# in asp.net.i used microsoft office dll but exception raises. if i will use stream reader and file stream class then some rectangle boxes are coming in place of empty space.pls give me some idea about it. i saw ur site but there also exception raises.i am trying also register that dll in own computer but some warning cames that :-this dll or path id doesn't exist ...so what should i do...?
  
 
Thank you