I own a Toshiba satellite c675-s7200, which came with a hitachi 320gb 5400rpm HDD. After about 6 months, the hard drive started making clicking noises and the laptop failed to boot. I needed a quick fix, so i went to wal-mart and bought an 2.5" Toshiba external hard drive (because they dont sell internals) and took the hard drive out of the external case and installed it into the laptop. I was able to run windows 7 for about an hour until this hard drive failed in the exact same way. I ran memtest86 and memory is good. Did I just buy a bad drive, or is it maybe a PSU issue? I'm about to give up.