I had to reinstall Windows XP on my Aspire 5720 and now I'm reinstalling the drivers. There are two touchpad drivers and I don't know how to find out which is the right one for my system. I've run the program Acer provides that looks at your hardware, but it doesn't tell me which touchpad I have. The two drivers are Alps and Synaptics -- is there any way I can determine which one I need? Thanks!