I'm getting the same error on a Toshiba Satellite A55-1064 laptop. That is, /dev/sda exists, but /dev/sda1 doesn't exist, even though it should. The hard drive is listed as "40GB (5400 RPM); Enhanced IDE (ATA-6) hard disk drive." The MBR on the hard drive is not messed up. QTParted and GParted both report the hard drive as I expect (/dev/sda, with /dev/sda1 being the only partition and filling the entire drive). The partition has a windows install on it, and is NTFS. Windows can boot, but fails after about two minutes, still in the loading screen. I'm using the lastest knoppix cd.