I pulled some failed hard drives from one of our servers, put in two new drives, configured them into a RAID 1 array, then put in the Windows 2008 R2 disk and waited for the "Press any key to boot from CD" message to appear, but instead it was just a black screen with a white blinking cursor. Stayed that way for several minutes.
I've seen this before on other windows installs, but the answer to solving it was always different. Sometimes it meant bad media. One time randomly mashing keys made it work on a different machine.
So to reiterate, trying to install Win Server 2008 R2 on to a new RAID 1 array that has never had an OS installed before.
Any idea why this might be happening in this case?