My laptop installed with two operating systems: Windows 7 home basic and Ubuntu Linux 11.04 fails to restart. I tried to do the error check and get this message: the file or directory H:\found.000\dir0000.chk is corrupt and unreadable. please run the Chkdsk utility. Then tried to run Chkdsk/r through prompt command in safe mode and get the following message: "The type of the file system is NTFS- Cannot lock current drive- Windows cannot run disk checking on this volume because it is write protected-". Any help or advise is welcome and appreciated.