Why won't the optifine mod install on minecraft?

For mod users only! When ever I play minecraft Its so laggy and I read that it helps with the lag, so I decided to get the optifine mod. But the thing is, The installer on the link doesn't work. I always use that certain installer but this time I click install and all it does is "download" then says and I quote "Optifine Mod Installed" then I look on the install button and is says install mod. It doesn't say Optifine mod installed. Please help I'm getting tired of the lag and I need some help!

I'm not the best with computers, but I used this tutorial ----->

Heres how to do it
1)Download it and save it
2) right click it and click "Open With" open it with java
3) Click install (the top option should be checked, others don't need to be)
4) go to your minecraft launcher and click your name in the bottom left
5) click Optifine
6)Play

Here's the official Optifine site: http://optifine.net/...nloads.php don't do it from a forum since Optifine.net comes from the maker.