Recovering Previous Versions of a File
Windows 7 Professional,
Enterprise, and Ultimate editions enable you to restore a previous
version of a file. This is handy if a data file has been edited and the
changes are not an improvement, or if a user who intended to save a new
version of a file with File, Save As accidentally clicked File, Save
instead and overwrote the previous version.
There are two sources for previous versions:
If
you have overwritten a file and want to retrieve a previous version,
right-click the file and select Properties. Click the Previous Versions
tab to see what backup or shadow copies may exist (see Figure 1).
If more than one previous version exists, select the one you want to use, and choose from the following options:
Open— The previous version is opened by the default application for the file type. The current version is retained.
Copy— The previous version is copied to the destination you specify.
Restore—
The previous version replaces the current version. After selecting this
option, you must click Restore to confirm the operation.
If you use Windows XP and
Windows 7 in a dual-boot configuration and Windows XP mounts drives that
contain Windows 7 system restore points, Windows 7 will delete those
restore points the next time Windows 7 is booted. When the restore
points are deleted, any shadow copies contained there are also deleted.
If
you use a dual-boot XP/Windows 7 configuration, don’t mount Windows 7
drives with Window XP. To prevent Windows 7 drives from being mounted by
Windows XP, use the techniques described in KB926185, available at http://support.microsoft.com.
(Though this KB is based on Vista and Server 2008, the information
still applies to Windows 7.) These methods include creating a new
Registry subkey in Windows XP, which prevents XP from mounting the
specified drive letter, or using BitLocker on the Ultimate or Enterprise
editions of Windows 7 to prevent XP from mounting encrypted drives.
Security Policy Configuration Options
USB flash memory drives
are becoming ubiquitous. I carry one around most of the time for quick
and easy file transfers, and they’ve found their way onto many keychains
and even a few ballpoint pens and Swiss army knife models. Although USB
flash memory drives are handy for data transfer, for improving Windows
performance with ReadyBoost, and as a method for providing BitLocker
credentials, they are a two-edged sword: They can also be used to steal
confidential data, even from systems that use BitLocker or EFS
encryption. After all, these encryption methods block unauthorized users
from gaining access to data, but they can’t stop the authorized user
from walking off with data.
In the past, institutions
have used fairly crude methods for blocking access by USB devices, even
to the point of literally gluing USB ports closed. However, in an era
in which parallel, serial, and PS2 devices have been relegated to the
boneyard by USB devices, more intelligent management of USB device
security is needed. In Windows 7, you can use various Group Policy
settings, including the following, to prevent removable-media drives,
including USB flash memory drives, from being used to snatch data, while
still permitting legitimate uses for printing, input devices, and so
forth:
You
can also block installation of unapproved devices, such as USB flash
memory drives, or permit only installation of approved devices. For
details, see “Step-By-Step Guide to Controlling Device Installation and
Usage with Group Policy,” at the Microsoft TechNet website.
Third-Party Disc-Backup Tools
Although Windows 7
breaks new ground for Microsoft in its support for both image and
file/folder backups, you might still prefer to use third-party backup
tools, for the following reasons:
Support for existing backup file types—
If you want to be able to access existing backups with Windows 7, you
need to use a version of your existing backup software that works with
Windows 7. Consult your backup software vendor for specific
recommendations.
Capability to extract files from an image backup without scripting—
The most recent versions of leading image-backup programs such as
Acronis True Image and Symantec Norton Ghost also support individual
file/folder restoration from an easy-to-use GUI. Windows 7’s system
image can be used for file/folder restoration only through the use of
the wbadmin command-line tool.
Support
for advanced backup options such as compression, splitting of a backup
into smaller files, password protection, and others— If you want these or other advanced options, you must use a third-party backup program.
Support for tape backups and tape libraries—
Windows 7’s backup features do not include support for tape backups and
tape libraries, although many third-party backup programs support tape
as well as external drives, network shares, and CD or DVD backups.
Because
of the extensive changes Windows 7 makes to the structure of user file
storage and how the OS works, you will probably need to upgrade existing
backup programs to versions made especially for Windows 7. Contact your
backup vendor for details.
