Compaq Presario CQ40 - "Unmountable Boot Volume" Error

Hello,
I have a Compaq Presario CQ40 which doesn't want to boot up. It starts ok, asks me if I want to start windows normally goes on to the black screen where the windows logo come up then from there things start to go downhill. A blue screen appears just for a flash and then it restarts. The flash is so quick that I had to take a video and then dissect it frame by frame to read what it said. It says "Unmountable boot volume"

I originally had a windows vista installed, then it crashed after a few years, then a friend of mine erased everything (including the partitions) and installed a windows 7 on it. So, it currently has a windows 7 installed. I have tested both memories, they seem to work fine. Quick hard disk self test passed too. I do not have a recovery disc, tapping the F10, F11 or F12 doesn't take me into the recovery mode. Tried the BIOS too as per some other suggestions online, no joy.

Any help will be highly appreciated.