Hi
Have you an option in the bios for Raid?
If so just enable it!
Then as the rig boots, you should see it say "Ctrl + I" to enter Raid setup!
Just go in there and follow your nose and make the "Stripe Raid" choosing the 2x 500GB drives!
Then continue to install Windows.
When you are installing you should just see two drives.
Install to the raid array, then in windows 7 you can use the "Backup and Restore" to make an Image of the Raid Array! On the 1TB drive
Then if things go wrong, you just boot with the Windows disk and restore from Backup
As for auto backup! I don't think it's possible!

Have you an option in the bios for Raid?
If so just enable it!
Then as the rig boots, you should see it say "Ctrl + I" to enter Raid setup!
Just go in there and follow your nose and make the "Stripe Raid" choosing the 2x 500GB drives!
Then continue to install Windows.
When you are installing you should just see two drives.
Install to the raid array, then in windows 7 you can use the "Backup and Restore" to make an Image of the Raid Array! On the 1TB drive

Then if things go wrong, you just boot with the Windows disk and restore from Backup

As for auto backup! I don't think it's possible!