This was driving me nuts with a new motherboard, and I can’t believe I had to google for so long to find the answer.
Symptom: You can use the keyboard to change BIOS settings, eg. Boot order, but after that, when you get to “Press any key to boot from DVD”, it’s unresponsive and times out and boots from the hard drive instead. Additionally, subsequent screens before windows, eg. System Recovery, or Login, are also unresponsive to the keyboard.
Solution: In your BIOS, find a page called “Integrated peripherals” or “Advanced settings” and look for a setting called “USB keyboard” or “Legacy USB” and make sure it’s enabled.
I also saw a solution that was to disable the “USB mouse”, which shouldn’t have worked, but did – and was ok because this setting is for USB before windows starts. Once in windows, windows uses its own drivers to access the mouse.
Explanation: This is a BIOS setting, which, if disabled, is meant to prevent people plugging in their own keyboards into server computers to tamper with them. It was disabled by default on my motherboard, and was particularly frustrating because I thought it already worked first time, when actually it was because on the first run I had blank HDDs so it had no choice but to boot from the DVD. But once I had bootable HHDs… I had no way of getting it to boot from the DVD. This solved the problem.