Buy a Windows 7 DVD. Lots of places still have them in stock. Then boot from the DVD, format the drive and install Windows 7. After that, go to the ASUS website and download drivers if you are having an issue with something. It *may* work fine without any drivers from ASUS.
As cheap as hard drives are, I would buy a new drive to install Win7 on and keep the Win8 drive just in case. Should something go wrong with the Win7 install (lack of driver support might be an issue), then you could always go back to the original drive. Should Win8.1 resolve whatever issues you have with Win8 you would still have that option as well.
Concur with itpro , espeacialy since you are tinking of buying a SSD.
1) Yes down load all the win 7 drivers.
2) NO but that is NOT a problem. Windows 7 has an excellent Back-up app.
... Once you complete the windows 7 installation and all looks GOOD. Goto controll panel, elect back up, then on left side select create a system image. Since this is a single drive laptop, recommend you put the image on your back-up USB HDD - don't have, not nice (LOL). Should you ever need to "reinstall" windows, just pop in the repair disk (or windows installation disk), boot to the DVD, select repair, then restore from image - WALLA, 15 minutes later you reboot to the exact state the system was in when you created the image. NO re-install windows, wait for windows updates, no reinstall drivers and programs. Will not even have to re-activate windows. ONLY will have to re-load what ever changes were made after the image was created.
NOTE: for a single drive laptop, a 60 gig SSD is just to SMALL, also they are not cost effect when compared to a 120/128 gig SSD.
There are several things you need to do for a SSD, while installation is basically identical for SSDs and HDDs there are some minor diff, and tweeks you should do for a SSD. Such as:
.. Verify BIOS is set to AHCI, not IDE
.. Disconnect HDD before installing OS to SSD (Not a problem for a single drive Laptiop)
.. After installation to SSD need to 1) verify defrag is DISABLED, disable hibernation ect