Is It Possible To Mod MineCraft on USB? How?

I Recently added Mine Craft on my portable USB, most computers I plug it into are low tech and can't run MC too well. It is possible to play, however, the lag is unbearable. Is there anyway i can add OptiFine to my game? I'm on the latest Version (1.7.4) and have attempted numerous times to mod the USB's MineCraft data.
I have tried Duplicating the Version and replacing it with OptiFine's (dot)JAR file, no success.
I have tried regular ways to install it but it can't find the MC files, for it is searching in the Computers "C" Drive and the Removable USB. I have Googled this question for some time now and I couldn't find anything close to "Modding USB MineCraft."

YES SEARCH IN YOUTUBE

You need Optifine HD C7 Standard for Minecraft 1.7.4 WARNING: DO NOT USE ULTRA IT IS EXTREMLY BUGGY
1.Download Optifine HD C7 Standard for Minecraft 1.7.4 on http://www.minecraftforum.net/...much-more/
2.Open the Optifine HD C7 Standard file and it will say This installer will… Then click Install on the bottom left corner and done you have Optifine HD C7 Standard!
3.Click Profiles in your Minecraft Launcher and choose Optifine then run the game and DONE!