Ok try this. Click Start, Click Run.
Type regedit in run box and run it.
Click the + next to HKEY_LOCAL_MACHINE
Click the + next to software
Scroll down to Wow6432Node and change the registry value to
Do it exactly like this and make sure not to mess with anything else in the registry.
The problem your having with Asus update is because you installed a Creative Sound card. The registry I told you to change is for 64bit OS support and is the root of your update problem. You could deleet this registry compleetly without anything bad happening but adding an a to it is just as good and you never know if you might want to enable it again by deleeting the a.
This happens to all Asus A8N Boards if they install a Creative audigy or X-Fi sound card. I am going to post this fix in the MoBo section right now.