There is not even a hint in your request as to what you need. With the lack of info on your part, all I can suggest is to visit the Acer website to see if they have what you're needing. Or if you can tell me, I might be able to help. I can say this.... if Acer never shipped this machine with Windows 7 installed, it will be more difficult to find a working Windows 7 driver.
In the meantime, you can check this site for available drivers: http://www.helpjet.net/files-Acer-Extensa-5620Z.html
and there's some upgrade instructions on this page: http://www.instructables.com/id/Acer...verhaul-Guide/
Acer Extenza 5620z Laptop