you can download acer aspire 4715z driver for windows vista sp1 from the link below. note that all the downloads below ONLY for WINDOWS VISTA SP1. Please make sure you have Vista SP1 installed before you install the drivers.
after updating your windows vista installation with sp1, you might notice that your hard drive free space has significantly decreased. this happened because when you install vista sp1, windows will automatically save your old system files in case some day later you would like to revert to your old version of vista .