Simplify the following text for a Grade 8 native English-speaking person.
Original: The first beta for Windows 2000 was released in September 1997 and several further betas followed until Beta 3 which was released on 29 April 1999 .
Simplified: The first software test version ( also known as a beta version ) for Windows 2000 was released on September 27 , 1997 . Several more test versions were released until Beta 3 , which was released on April 29 , 1999 .