Cannot run unity web player. help needed urgent.

Hi friends.

I installed unitywebplayer from the unity3d website. i installed the plugin. after successful installation i got the details of the webplayer version and engine as

Unity Plugin version:2.6.1f3 Unity Engine version:2.6.1f3

but still i cant view the demo page. it is asking for installing the plugin manually. i even tried downloading the manual plugin which came for download. but it didnt contain any installation files. so please guys help me in this regard. as this is very important to me as my final year project is based on this web based 3d demonstration. help me please asap.