1. I get the message 'No hard disk was found' and then it goes away and the ASUS screen comes up again (even though my hard drive IS working)
This message occurs because the BIOS thinks you may have a RAID installed but because you do not it displays the message. You can ignore this message.
2. It asks me to select either 'Windows 7' or 'Windows 7' ..I always select the first option and the PC boots up fine.
The second option is probably to boot from the recovery partition, it is easy to get rid of this by downloading the program BCDedit You can use it as a free user.http://www.sevenforums.com/tutorials/2676-bcdedit-how-use.html