We recently experienced a power failure. On restarting my PC, I get the "....Windows did not start succesfully" message and the usual options.
In BIOS it recognises the HDD's installed and this is a system that I've used for several years and have not made any recent changes.
In the POST it tells me that on IDE 0 and 1 that there is "No Device" and loops round trying to restart only to find the same whatever option you choose.
It's been a few years since I built and configured a PC and I have a room full of bits to build probably a few more but this old dog has never failed and I've used it since XP came out and it does the job. I can probably recover any data on there hopefully. I'm not sure if I need anything on there but I'd like to check though.
Sorry if this is a repeat but this is my first post on here.
While I know you had a power failure but try to unplug and plug back in the cables for your H.D. Listen and see if the HD spins up, starts getting warm after 5 min. proving that its running.
Make sure the bios is set to booting from HD.
You could try to get a external drive bay and put your HD into it and see if you can see the data.