Strange PartitionType

Hi all,

When I’m using the internal format command in Windows XP on my
virtual disk it want to set a strange PartitionType.

IOCTL_DISK_SET_PARTITION_INFO gives a
SET_PARTITION_INFORMATION struct which contains a UCHAR
called PartitionType. This value is set to 91, or for you that speak hex 5b.

I can’t find any corresponing PartitionType in the manual.
IsRecognizedPartition, IsFTPartition and IsContainerPartition all
returns FALSE.

Do you know why I get this value?

Regards,
Daniel Öberg