How can I install ableton lite?

My sister wants to install it on her laptop because she got a soundpad on her birthday. We already have the start setup on it, but when we want to install it, we get a message that the system administrator has prevented this. How can I fix this? I've already looked and haven't really found an answer.

Are you logged in as an admin?

You can also right click on the file and select "run as administrator".