HOW TO CREATE SIMPLE SPEECH APPLICATION IN WINDOWS FORM ?

Dear Programmers,

I want to know how to create a simple speech application in windows form application? i.e while am pressing keys it should say what key i pressed .

Also,

Like AVAST. i.e. Once scan completed means it says "Scan Has been Completed" . Like this i need...

please help me . I am eagerly waiting for u r reply...