Rich said:
I have a SanDisk Cruzer 16 GB USB Drive.
The other day, I needed to download a Dell Diagnostics utility to it. I did
so - to make it bootable, the utility modified it to a 2 GB partition with
12.95 GB unallocated. That went fine.
I figured I would be able to re-partition it to its original 16 GB size.
Now, in Computer Management/Disk Management, I'm seeing the two partitions.
the first one is 1.97 GB FAT32. The 2nd partition is "12.95 GB Unallocated."
If I right-click on the first partition, I can do the usual, Change drive
letter, Format, etc.
However, when I right-click on the second, my only choices are to go into
Properties or Help. "New Partition..." is grayed out.
I have go into the properies of the drive and changed to "Optimize for
Performance" . . . to no avail.
What do I need to do to get my 16 GB back?
Thanks . . .
If you can't find an intelligent way in Windows, to completely erase the
drive, I have a dumb way to do it
First, close your Disk Management window.
Download this program. It runs from a DOS (command window) prompt.
http://www.chrysocome.net/dd
First, run
dd --list
to get the names of the storage devices. The above web page has
examples. To play along here, I'm going to erase my 8GB USB flash.
Basically, I go on size here. I see two entries that are consistent
with my 8GB flash. The "Removable media" is a clue too
\\?\Device\Harddisk2\Partition0
Removable media other than floppy. Block size = 512
size is 8019509248 bytes
\\?\Device\Harddisk2\Partition1
Removable media other than floppy. Block size = 512
size is 8013233152 bytes
"Partition0" is the whole disk. "Partition1" is the first actual partition.
The size of each should also be a hint. We want "Partition0" for our
erase operation, as it effectively treats the whole "raw" device
starting at sector 0.
There is a bug in this Windows version of "dd", so we have to use
an exact command for the erase. 8019509248 = 7648 * 1024 * 1024.
I'm going to make my blocksize 1048576. The count of those blocks
is going to be 7648. So this is the next command I issue in the
command window. This erases the whole thing, exactly, and doesn't
rely on the command figuring out where the end of the disk is.
dd if=/dev/zero of=\\?\Device\Harddisk2\Partition0 bs=1048576 count=7648
The command should say it has processed 7648 records. Be *very* careful
with the command syntax, to make sure you're zeroing out the correct disk!
When you're finished, reopen Disk Management and it should be nulled
out.
It isn't necessary to erase the whole device. We could have erased just
a small portion, and that likely would have been enough to beat some
sense into Disk Management. Like erasing just the first megabyte would
likely have been enough. But if you "meet resistance", then erasing
the whole thing should do it. (This runs a bit faster. The other command
took probably about 8 minutes.)
dd if=/dev/zero of=\\?\Device\Harddisk2\Partition0 bs=1048576 count=1
Now, the funny thing is, when I go to Disk Management, it shows
7.46GB "Healthy" and "Active", and I'm not offered the ability to
delete partition. If I look in explorer, and try to open my J:
drive (the removable 8GB flash), it offers to format it. So
explorer knows there is nothing on there. But Disk Management
doesn't show it as Unallocated. I tried to change it to
"Optimize for Performance", but I'm still not getting the
option to format NTFS. Time to remove it and try again I guess.
I still can't get NTFS in the Format menu. But I have other ways to fix that.
HTH,
Paul
