Not sure about the correct english error message, since I have the localized Swedish version. But sometimes I get an error in Explorer, when clicking on a hard disk. The computer freezes and after a minute or so I get a message "A delayed write has failed, try to save the file F:\$mft somewhere else" or something. (the file name usually begins with a $ sign, I have no idea what it is) This has happened a few times. This last time, I also got an error message at boot up saying "Non system disk...". Turning off the computer for a while solved it. This latter problem with the HD:s not being found happens a lot with my brand new ASUS P4-T533.