How to make my Minecraft run faster? I have Optifine?

Right click Computer.
Click properties.
Click "Advanced system settings".
Click "Environment Variables".
Under system variables, find the Path variable.
Click edit, and append to the end of the value: ;"c:\Program Files\Java\jre7\bin". If you use 32-bit Java on a 64-bit OS use: ;"c:\Program Files (x86)\Java\jre7\bin"
Restart your computer.
Now re-open the command prompt and try again.