I've yet to use mine and leave it turned off. I did install the driver for it though. For me the touchpad driver was a pain. The Acer supplied driver for windows 7 wouldn't install, it would error out and fail. The Synaptic driver worked sort of, but the scroll button didn't work. After hunting around the Acer site I eventually found a version that worked. That also got the blue row of media keys working that I didn't know where actually attached to the touch pad. Sometimes it cab be a pain, even when you think you know what you're doing.
Some manufactures will have a hardware detection utility available for just this situation. I don't know if Acer offers one, I'm in the middle of something at the moment but I'll have a look when I get a chance. programs like Speccy might help. Speccy - Download