The T605 uses a Broadcom SATA controller for the onboard SATA (which includes the optical drive, but NOT the drives connected to the SAS 6/iR). Try this driver (run it to extract the contents first) ... this is not a common device, so was never considered for inclusion in the Server driver files by Microsoft: www.dell.com/.../poweredge-t605 If this does not do the trick, then, 9 times out of 10, the CD/DVD device driver message indicates bad OS media.  I would try installing via USB (which will also fix the above issue), burning the ISO again, burning it with different software or on a different machine, burning it at a slower speed, and/or downloading the ISO again, using a download manager to ensure the download integrity, if necessary.
I am trying to install windows 2008 R2 on a Dell PE T605, but I get the "A required CD\DVD device driver is missing." message when setup starts, and I am trying to load the driver for the Dell SAS 6/IR Adapter driver with no success. Is Windows 2008 R2 supposed to discover this driver automatically? And, if not, where can I find this driver? Your support will be most appreciated as I need to complete this install ASAP. Thanks in advance.
Install Windows 2008 R2 on a Dell PowerEdge T605