Cannot install Windows 7 on Dell Optiplex 755 using RAID 1 with 2TB drives

I have a Dell Optiplex 755 that was originally shipped with WinXP Pro and setup using RAID 1 (Mirrored).  I purchased a pair of 2TB hard drives, set them up as RAID 1, and proceeded to install Windows 7 Pro.  The installed almost finishes but then gives the following error "Windows Setup could not configure Windows to run on this computer's hardware".

If I don't use RAID and install the OS on a single drive, the install finishes and the system boots correctly.

I have tried using the following RAID settings "RAID Autodetect / AHCI", "RAID Autodetect / ATA" and "RAID ON".  I get the same result on all settings.

I even tried installing an image of a working single drive OS and could not get it to boot. (Problem could have been due to the imaging software not installing a bootable image correctly, not sure as I have never used "EaseUS Disk Copy" before)

I did find a statement on the Internet where someone said that the AHCI driver has problems with drives over 2TB, I guess he ment 2TB and above?  I am not sure, is this true?

Does anybody know if you can use 2TB set as RAID 1 on this machine, and if not, can I use smaller drivers with Windows 7 Pro such as 1 TB.