Was this an upgrade installation from Vista or Win7 or a clean installation. Upgrade installs can be really problematic and always normally recomend a clean install if possible.
Have you ded the latest chipset drivers for your motherboard from the ASUS web site, DO NOT USE programs like driver detective, slim drivers free, driver finder etc.
try the latest drivers from the ASUS site 1st, also don't forget to run windows update, have you logged in with a local account or a Microsoft account?
If these ideas don't work then would sugest a refresh of the installation. have a look here http://www.eightforums.com/tutorials/18052-refresh-reset-windows-8-without-installation-disk.html?filter1=Performance Maintenance