Cannot Save Changes to Bootsector using DiskProbe

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SUMMARY

When you use the Windows NT 4.0 Resource Kit application DiskProbe to edit a boot sector, the changes are not saved or written to disk if the currently loaded sector is not a recognized boot sector.

MORE INFORMATION

DiskProbe performs a string compare on the OEM String field to determine if the data in the sector buffer is a boot sector. This is an eight-character field that begins at offset 0x03 in the boot sector. Only the first four characters are compared, and the comparison is case sensitive. DiskProbe recognizes the following values:

   Value     Description
   ---------------------

   MSDOS     FAT formatted under MS-DOS or Windows NT 3.X on X86 platforms.

   MSWIN     FAT formatted under Windows 95.

   WINNT     FAT formatted under Windows NT 3.X or 4.0 on RISC platforms.

   NTFS      NTFS formatted under Windows NT 3.X or 4.0 on any platform.

1. Read the sector into memory. Be sure only a single sector is loaded into memory.

2. On the View menu, click the appropriate boot sector view.

3. Edit the OEM String field so that the first four characters match one of of the expected values. Remember that FAT Bootsector View will not accept "NTFS" and NTFS Bootsector View will not accept any of the FAT values.

4. On the View menu, click Byte View.

5. On the Sectors menu, click Write. Be sure the handle, starting sector, and number of sectors are correct, and then write the change to disk.

6. On the Sectors menu, click Read. Read the current sector into memory.

7. Switch to the appropriate boot sector view and edit the desired field. Changes will now be saved correctly.