Why unity web player doesn't work in IE7 , IE8 ?

Hi I need to publishing a demo game in web player mode, but, when I try to play the game in IE it’s impossible, just shows the image to install the player and then the user installs the player, and reload the browser again, shows the same image over and over again.

What can I do?

please help me!!!
thanks for everything.

The web player is regularly tested in IE7 and IE8. If you share up the link to your website, we can check it out for you.