1. Go to this site:
http://support.asus.com/download.aspx?SLanguage=en&p=3&s=114&m=X53E&os=&hashedid=mDFYFQWEpTitMwA6
2. Select your OS
3. and you should find all the drivers you need.
Good indication. The bare minimum you'll normally need is indeed the Network Adapter driver, from whence you'll be able to download everything else from the new Windows 7 install. What I usually do is download the said driver to my phone or to a USB drive (whenever a second computer is available, which appears to be the case here), plug whichever into the other computer and go from there.
You're almost done!
JD