I noticed that a few people didnt know how to install optifine so i will make this as simple as i can. If you dont know what optifine is, its adds more options in your options and stops lag.

1. Link to optifine download http://www.minecraftforum.net/topic/249637-145-optifine-hd-d4-fps-boost-hd-textures-aa-af-and-much-more/

2. Click the download you want and press save. Then once its downloaded click open folder, it should take you to your downloads.

3. Open the optifine WinRAR ZIP you downloaded.

4. Go to your appdata and click Roaming, at the top you should see .minecraftclick on that and then click on bin.

5. There should be something called minecraft, right click and press open with WinRAR archiver.

6. Delete a folder called META-INF its a mod protector, if you dont delete it minecraft will open witha black screen when you put optifine inminecraftsfile.

7. Drag all the files in the optifine download exept the top one into the minecraft file that you should all ready have open.

8. If a new optifine version comes out just do the same as if you didnt have optifine already, you dont need to delete anything either, but it a new minecraft version comes out you need to delete META-INF again before you put the new version of optifine in.

9. And thats it you ready to play minecraft with hardly any lag at all! :D

Hope this tutorial help, if it did please subscribe! :)

THIS IS OLD AND ONLY WORKS ON 1.5.2 OR EARLIER ILL MAKE A NEWER ONE LATER ON!!