I need an opinion of a professional hdd master, I have this problem with 2 hard drives. Hitachi and Seagat. When I load OS, or try to load Rad Studio, I hear this sound. This sound repeats again and again for hours. I don't understand what's wrong with my hard drives. What causes this sound? On internet forums I usually hear "do a backup and buy a new disc". But my Seagate is new and producws this annoying sound, it always loses system liles, checkdisc always performing checking when I start my computer and correcting lots of system files, sometimes it works good, but sometimes hdd produces this sound and computer slows down at the moments when it makes this scratching noise. Recently my second hdd Hitachi started to produce the same noise when i start computer and it loads os, very often these scratching noises follow dark screen with the message "ntldr is missing" on it, if this sound starts when hdd is working it slows down computer. Please listen and say what do these sounds mean.