Copy league to USB question

So if you go to the third page of that discussion in the link section you'll see it mentions that all you have to do to get league working on a USB is to:

1. Install and patch on a computer up-to-date.

2. go to hard drive and copy the folder 'Riot Games' into the USB

after that its pretty much done. Fairly simple but I have a question in regards to it...

If i were to copy it onto the USB could it then be uninstalled from the computer since the game is on the USB?

...In the discussion it makes a mention of people who can't run the game on other computers because it has an imprint from the original computer. My only reason for needing to know is that I don't want to bog the memory of the original computer as it isn't mine.

So... ?