Remix texture pack HD
Make sure your Game is clean, by deleting the Files version, minecraft.original.jar, minecraft.mrmbackup.jar and minecraft-1.1_02.jar in your bin Folder (if those files exist)
(Type %appdata%\.minecraft\bin in your Windows search or execute bar to get there).
If you have never installed any mod or Texture Pack, you can skip this step.
Load Minecraft once to Download the latest Version
Make sure you don't have any Texture Packs in your texturepacks folder
Download and run the latest HD Texture fix by Xau
Check Texture Pack and browse to Remix Pack HD
Ensure the Tile Size is 128x128 and all boxes below a ticked (if you get a black screen when loading Minecraft try unchecking custom Lava and Water)
Once its done close the Patcher and run Minecraft normally
Mac and Linux: May be different, so for specific instructions for your OS please look somewhere else on the Internet for now.
Because this is a HD texture pack, you will need to use the MCPatcher first!