Fixboot

The partition's first sector is also known as the boot sector. What the MBR is for entire drive, that boot sector is for an individual partition: like the MBR, the boot sector contains information that the system needs to locate the materials that are needed to start the operating system. A corrupt or missing boot sector is a serious problem. Without it the partition cannot be accessed.

Possible (but not all) symptoms are:

Invalid media type reading drive
Abort, Retry, Fail?
File system is displayed as RAW
Windows may ask if you want to format the drive
File names contain weird characters
Sector not found messages
If boot sector of one FAT16/FAT32/NTFS partition was corrupt, Partition Table Doctor will mark it with "X".

If you cannot access the FAT16/NTFS partition and the partition was marked with "X" right click the partition and choose Fixboot. Partition Table Doctor will automatically check and repair the boot sector of the partition.

If you cannot access the FAT32 partition and the partition was marked with "X" right click the partition and choose Fixboot. There are two choices:

Auto mode: Partition Table Doctor will automatically check and repair the boot sector of the partition. We recommend you choose this mode. If Auto mode doesn't work, you could choose. Interactive mode: You must input the Label for the partition or file name (the file is in the Root Folder). If you do not know what file name to input, follow the file name that is suggested:?

Bootable partition:

io.sys
msdos.sys
ntldr
bootlog.txt
Other partitions:

_restore
Recycled
File name cannot support long name or wildcard character by DOS version of Partition Table Doctor.

Browse:

In both of the modes, Partition Table Doctor will provide you a preview of the folders and files in the root directory on this partition before Yes option being chosen to make the change valid on a dialogue box. If it appears the same as the previous one that means this function can fix it.

Note:
For FAT16/FAT32 partition, Fixboot is very good at repairing boot sector of partition.

For NTFS partition, even if boot sector is correct but MFT (Master File Table) is corrupt, symptoms are the same. We recommend you download the demo version of Partition Table Doctor to check whether boot sector of partition was corrupt.

Most, scandisk will destroy more than they retrieve. Please stop scandisk from starting at logon: Opening msconfig and then clicking advanced there was the option to disable scandisk after a bad shutdown.