 Contents
Understanding disk compression
A compressed drive is not a real disk drive, although it appears
that way to Windows and your programs. The contents of a
compressed drive are stored in a single file, called a compressed
volume file (CVF), which is located on an uncompressed drive,
called a host drive.
For example, suppose you want to compress your hard disk, drive
C. The first thing DriveSpace does is assign a different drive
letter to your disk, such as H. Drive H will be the host for
drive C. DriveSpace then compresses the contents of your hard
disk into a compressed volume file stored on drive H. To Windows
and your programs, the compressed volume file on drive H will
appear to be your original drive C, but drive C will have more
free space than it originally had.
When you view the contents of your computer by using My Computer
or Windows Explorer, the host drive is hidden unless it contains
more than 2 MB of free space. If it contains more than 2 MB of
free space, it will be visible and you can work with it as you
would any other drive.
In addition to compressing the contents of an entire drive,
DriveSpace can use the free space on an uncompressed drive to
create a new, empty compressed drive. For example, instead of
compressing drive C, you could use 10 MB of the free space on
drive C to create a new drive, drive G. Drive G will contain
approximately 20 MB of free space.


DoubleSpace and DriveSpace compatibility
DriveSpace for Windows supports drives that were compressed using
DoubleSpace (which was included in MS-DOS versions 6.0 and 6.2)
as well as DriveSpace for MS-DOS (which was included in MS-DOS
version 6.22). You can use DriveSpace and DoubleSpace drives
interchangeably. For example, you can use floppy disks that were
compressed using either DoubleSpace or DriveSpace. However, such
floppy disks can be used only in computers that have DriveSpace
for Windows or DoubleSpace installed.
If you have drives that were compressed using either DoubleSpace
or DriveSpace, you can configure them by using DriveSpace for
Windows.


To compress a drive
1    Click the drive you want to compress.
2    On the Drive menu, click Compress.
3    Click Start.
4    If you have not backed up your files, click Back Up Files,
and then follow the instructions on your screen. When you are
done, proceed to step 5.
5    Click Compress Now.
6     If Windows prompts you to restart your computer, click Yes.


To uncompress a drive
1    Click the drive you want to uncompress.
2    On the Drive menu, click Uncompress.
3    Click Start.
4    If you have not backed up your files, click Back Up Files,
and then follow the instructions on your screen. When you are
done, proceed to step 5.
5    Click Uncompress Now.


To adjust free space on a compressed or host drive
1    Click the compressed drive or host drive whose free space
you want to reallocate.
2    On the Drive menu, click Adjust Free Space.
3    Drag the slider.


To mount a compressed volume file
1    Select the drive that contains the compressed volume file
(CVF) you want to mount.
2    On the Advanced menu, click Mount.
3    Click the compressed volume file that you want to mount. 

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To unmount a compressed volume file
1    Click the compressed drive you want to unmount.
2    On the Advanced menu, click Unmount.

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 To create a new compressed drive
1    Click the drive whose free space you want to use to create a
new compressed drive.
2    On the Advanced menu, click Create Empty.
3    Change any settings as needed, and then click Start.
4    If Windows prompts you to restart your computer, click Yes.
Tip
     For Help on an item, click   at the top of the dialog box,
and then click the item.


To delete a compressed drive
1    Click the compressed drive you want to delete.
2    On the Advanced menu, click Delete.

To change the estimated compression ratio
1    Click the compressed drive whose ratio you want to change.
2    On the Advanced menu, click Change Ratio.
3    Drag the slider. 
Note
     Windows uses the estimated compression ratio to report how
much free space is available on the selected drive. Generally,
this value should match the Actual Compression Ratio. 


To use compressed floppy disks or other removable media
1    On the Advanced menu, click Settings.
2    Make sure the Automatically Mount New Compressed Devices box
is checked. 
3    Click OK, and then quit DriveSpace. 
     DriveSpace will now automatically mount compressed disks
that you insert in a drive.
Note
     DriveSpace does not automatically mount removable media
while the program is running. For information about mounting
media while DriveSpace is running, click Related Topics below.

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To check a drive if DriveSpace detects a disk error
1    Click here  !EF(`scandskw.exe',`',1,`') to start ScanDisk.
2    In the list, click the drive you were working with in
DriveSpace.
3    Make sure Thorough is selected, and then click Options.
4    Make sure System And Data Areas is selected, and that the
two boxes in this dialog box are not checked. Then click OK.
5    Click Advanced, and then make sure the Invalid Filenames and
Check Host Drive First boxes are checked. Then click OK.
6    Click Start.


A compressed volume file stores the contents of a compressed
drive. Compressed volume files are hidden and have names such as
Dblspace.000.


Host drives are uncompressed drives that contain compressed
volume files. They also typically contain some free space and
system files that cannot be compressed. 


Mounting a drive establishes a connection between a compressed
volume file (CVF) and a drive letter, so you can use the files
the CVF contains. 


The actual compression ratio is the compression ratio that
DriveSpace is currently achieving. For example, if the
compression ratio is 3.0 to 1, DriveSpace is compressing files to
one-third their original size.


Removing the DriveSpace compression driver
DriveSpace is ready to uncompress the last mounted compressed
drive on your computer. If you have no other unmounted compressed
drives, and do not intend to use compressed removable media, you
can probably remove the DriveSpace compression driver. For more
information, click a button below.
     Do I choose Yes or No?
     What if I change my mind?
     If I don't remove the compression driver now, can I do it
later?


If you are sure you won't need DriveSpace to provide access to
compressed drives in the future, click Yes. Choosing Yes removes
DriveSpace from memory.
If you want DriveSpace to remain in memory to provide access to
unmounted compressed drives and compressed removable media, click
No. This uses some additional memory.

If you remove the DriveSpace compression driver and then discover
that you need it to use unmounted compressed drives or compressed
removable media, carry out the following procedure.
1    Start DriveSpace.
2    On the Advanced menu, click Settings. 
3    Make sure Automatically Mount New Compressed Devices is
checked. 
Tip
     To print this topic, click it by using your right mouse
button, and then click Print Topic.


It's easier to remove the compression driver now and reenable it
later if you need to.


Click Help Topics to return to the list of topics.


Lists all the drives on your computer. To work with a compressed
drive, click it, and then use the commands on the Drive or
Advanced menu. To view the properties of a drive, double-click
it.


Shows how much space on this disk is currently free and how much
is currently being used. This disk's free space and capacity will
increase after you compress it.


Shows approximately how much free and used space will be on the
drive after the drive is compressed.


Begins the compression process. After you click Start, you will
have an opportunity to back up your files.


Click this to change settings for the compressed drive's host
drive. A host drive is an uncompressed drive on which a
compressed drive, which is actually a large hidden file, is
stored.


If this box is checked, Windows automatically mounts compressed
removable media, such as floppy disks, when they are inserted in
a drive. If this box is not checked, you must use the Mount
command on the Advanced menu each time you insert compressed
removable media in a drive.

Shows which version of the compression driver Windows is
currently using. This driver enables you to use your compressed
drives.


Shows which drive letter DriveSpace will use as the host drive
for the drive you are compressing. If you plan to use this drive
letter for another purpose, such as mapping to a network drive,
click a different drive letter.


Shows how much uncompressed free space will be set aside on the
host drive. To change this amount, select it, and then type a new
amount.


 If this box is checked, this drive will not appear in areas such
as My Computer, Windows Explorer, and Open and Save As dialog
boxes. 


Starts compressing this drive.


Starts uncompressing this drive.


Starts a backup program, which you can use to back up the files
on this drive.


Shows how much free and used space is currently on the selected
compressed drive and its host drive.


Shows how much free and used space will be on the host drive
after the compressed drive is uncompressed.

Starts uncompressing the selected drive. After you click Start,
you will have an opportunity to back up your files.


Shows which drive letter DriveSpace will use for the new
compressed drive. If you plan to use this drive letter for
another purpose, such as mapping to a network drive, click a
different drive letter.


Shows how much space DriveSpace will use to create the new drive.
To change the size of the new drive, select it, and then type a
new size.


Shows the uncompressed drive whose free space will be used to
create the new compressed drive.


Shows approximately how much free space the new compressed drive
will contain.


Shows how much space will remain on the uncompressed drive whose
free space is being used to create the new compressed drive.


Starts creating a new compressed drive.


Shows how much free and used space is on the compressed drive. If
you need more free space on the compressed drive, you can reduce
the size of the host drive by dragging the slider.


Shows how much free and used space is currently available on the
host drive. If you need more free space on the host drive, you
can reduce the size of the compressed drive by dragging the
slider.

Shifts free space between the compressed drive and its host
drive. There may be a red area on the left or right side of the
slider bar. If you move the slider into the red area, DriveSpace
will defragment the drive.


Shows the volume files on the selected drive that you can mount.
Volume files contain compressed drives.


Lists drive letters that you can assign to the host drive for the
selected volume file. If you plan to use the selected drive
letter for another purpose, such as mapping to a network drive,
select a different drive letter.


Shows the compression ratio DriveSpace is actually achieving. For
example, if the compression ratio is 3.0 to 1, DriveSpace is
compressing files to one-third their original size.


Displays the compression ratio Windows uses to estimate how much
free space is available on this drive. Changing the compression
ratio does not affect the degree of file compression. It affects
only the accuracy with which Windows reports free disk space.


Lists other drive letters that you can use if you want to free
the letter that DriveSpace assigned. This may be necessary if you
want to use the drive letter for another purpose, such as mapping
to a network drive.


Changes the estimated compression ratio.


Displays the name of the selected disk.


 Describes what type of disk is selected. 

Shows how much space on the selected disk is used and how much is
free.


Displays the total capacity of the selected disk.


Shows how much space on the selected disk is used (in blue) and
how much is free (in pink).


Displays the compression ratio that Windows uses to estimate how
much free space is available on this drive. 


Closes this dialog box and returns to the main DriveSpace screen.


Help is available for each item in this group. Click   at the top
of the dialog box, and then click the specific item you want
information about.