"A required drive device driver is missing."

Specs:
OS: Windows 7 Ultimate
CPU: Intel Core i7 2600K
Motherboard: Asus Sabertooth Z77
Memory: 8GB
Graphics Card: Asus Geforce GTX 660-TI
Hard Drives:
Kingston HyperX 3K 120GB
WD 2TB
WD 1TB


I installed a SSD on my about 1 year old system. I had a couple of problems while I wanted to install the OS on the SSD but I managed to create a new Hard Drive Partition and install the OS. At this point this was the "F:/" drive, and I had a dual boot with the "C:/" drive. Everything worked fine. Later I tried to format the C in my computer and change the "C:/" drive to "G:/" so I could have the SSD as the C:/ drive. Neither of these worked and I just recieved an error. When I rebooted the machine the message "BOOTMGR IS MISSING". I asked my friend for help, and he told me to do a clean windows install. So I burned an ISO image to a DVD-R disc at the lowest speed and booted up the disc. I clicked "Innstall Now" and after "setup is starting" I get the error message "A required drive device driver is missing. If you have a driver floppy disk; CD, DVD, or USB Flash Drive, please insert it now. Note: If the Windows installation media is in the CD/DVD drive, you can safely remove it for this step." I read on some forums that this is most likely the ISO image. So I downloaded a new one, and burnt it again. Still the same problem. I also tried to install Linux Ubuntu just to have an Operating System, but there also I got an error message: "Unable to find a medium containing Live file system". Any Help?

Where did you get Win7? How is it being activated?

The error is almost always a bad installer.

The installer should be booted to Clean Install Windows 7 deleting all partitions on the HD to create new as you please. It will always install to C if correctly booted to install. There is no reason to do it otherwise.

The problem wasn't the installation disk or the AHCI mode, the problem was the Disk ROM I was using. I was using a BD-Drive while changing to a DVD-RW drive, everything is working fine now. :)