Windows 7 - FAT32 Partition Types 0Bh and 0Ch? (corrected values here)

Asked By Bill in Co on 08-Jul-12 05:10 AM
Corrected this with the right values.  Sorry about that.

Well, this is really more a Win98 related tech question, but I thought I'd
ask here, since there are more gurus hanging around in here:

I was surprised to find that when I make two different backup copies of my
C: FAT32 boot partition to another drive, using BING (stored in separate
partitions there), that one of them shows as type 0Ch (12decimal), and the
other one shows as type 0Bh (11 decimal).   Does anybody know why?   (I am
using BING (BootItNG) in Maintenance Mode for this partition work).

Could it possibly have to do with one of them being stored in an Extended
partition?   (That one shows type 0Bh for some reason, even though the
original source was type 0Ch).


Paul replied to Bill in Co on 08-Jul-12 05:31 AM
This is what I keep in my bookmark collection.

http://www.win.tue.nl/~aeb/partitions/partition_types-1.html

That section of the page mentions this, but it is no longer available.

http://support.microsoft.com/support/msdn/sdk/platforms/doc/sdk/win32/95guide/src/fat32ovr_4.asp

If I go to Wikipedia, I get this.

http://en.wikipedia.org/wiki/File_Allocation_Table

0x0B and 0x0C. The latter type is also named FAT32X in order
to indicate usage of LBA disk access instead of CHS. On such
partitions, some CHS-related geometry entries in the EBPB record,
namely the number of sectors per track and the number of heads,
may contain no or misleading values and should not be used.

Win98 apparently has some size-related info stored in the
header of the file system, which causes problems if it is moved.
Maybe that is related to that description, not sure. I cannot
say I have had reason to move a Win98 partition, so I have never
experienced a problem like that. Usually, where I have got Win98,
it is all by itself.

HTH,
Paul
Bill in Co replied to Paul on 08-Jul-12 04:37 PM
Well, I was talking about my other computer, which does have Win98SE all by
itself.   But I was just making two partition "clone" backups (at least for
now, until I have determined which one I am going to retain).

Yes, I had seen the table of partition types.

But what is still unclear is to me is why BING stores one as 0BH (11 dec)
and one as 0CH (12 dec) when they are both the same.   I guess it has
something to do with one being stored in an extended partition on the backup
drive, and the other one, not.