Drivers for Windows

I recently gave Windows setup to my Acer Aspire One 725 netpad... 2GB RAM....AMD Dual Core C70 Radeon 6920/7920.....It was Windows 7 Ultimate 32-bit...I gave now Windows 7 64-bit and now I can't find my AMD stuffs...what are needed like drivers or softwares ??please give links....and also my touchpad works but the side arrows which makes it scroll up and down isnt working....also the fn keys are working but the Brightness one isn't.... Please help and give links of softwares and drivers I need to install to make it like before... Thanks