There isn't an installer to run in compatibility mode. You download the drivers from the website and it is just a folder full of sys and dll files.
I was able to get it working and I wish somebody had posted this explanation before. I had to figure it out the hard way. Here is the problem: when I go to the Asus website, the newest drivers that they have listed are dual mode drivers. The newest driver is Version 1.00.1.37. When you install it in WinXP, they work whether or not you have the controller in IDE/ATA mode or RAID mode (because the driver is a dual mode driver). The older drivers on the other hand only work when you have the bios set to that mode and have the correct driver installed for that mode.
For some reason Windows 7 can't handle the dual mode driver correctly and so you actually need to install the older driver which is a single mode driver. I had the BIOS set to have the controller be in IDE/ATA mode and I then installed the older Promise SATA378 Driver V1.00.0.26 (ATA Mode) driver for WinXp. It installed just fine, I rebooted, and presto! My drive was in My Computer!! I hope this helps others that have the same problem.