Microsoft

Put end-user system changes on ice with Deep Freeze

Techs who support PCs in an open environment get tired of end users tampering with their Windows settings, installing programs, and deleting Windows system files. Find out how Deep Freeze can undo any user-made changes with a simple system reboot.


End users tinkering with their desktop PCs can be a major headache for the help desk. But now there is a way to make end-user damage disappear by simply rebooting the PC, thanks to a product called Deep Freeze from Faronics Technologies.

How Deep Freeze works
Although Deep Freeze is a desktop lockdown utility, it operates differently than other such products. Instead of actively preventing end-user changes, Deep Freeze runs passively in the background. Users are free to make any changes to the system that they like. They can install programs, delete files, and change Windows settings. When the system is rebooted, though, all of the changes are undone and the system is restored to the state at which Deep Freeze was installed.

How does Deep Freeze accomplish this? According to Vik Khanna, director of sales for Faronics Technologies, once Deep Freeze is installed it "freezes" all the used space on a particular hard drive partition. No permanent changes can then be made to that partition unless Deep Freeze is disabled or uninstalled or Deep Freeze Professional's ThawSpace feature is used. Just how Deep Freeze manages to lock a partition's contents, Khanna wouldn't say—to protect Deep Freeze's patent pending technology. The process does not, however, involve any imaging of the hard drive; in fact, Khanna touts Deep Freeze as an alternative to the repeated imaging that is often performed on open-environment computers, such as those found in school computer labs or corporate training classrooms. It is in these environments that Deep Freeze really shines, and according to Khanna 16 of the 20 largest school systems in the United States currently use Deep Freeze, including New York City public schools, Los Angeles unified schools, and San Francisco unified schools.

But Deep Freeze's power doesn't come without a price. No permanent changes can be made to a partition once it has been frozen—including saving files. If a user saves a file to a "frozen" C: drive, it will be lost once the machine is rebooted—this includes information saved in Outlook PST files and Internet Explorer Favorites. Any programs that automatically save information to the frozen drive will need to be configured so they use an alternative location, such as a network drive or separate hard drive partition. Help desks must also configure their PCs to boot from the hard drive first for Deep Freeze to be totally effective. Otherwise, individuals would be able to boot from a floppy and bypass Deep Freeze.

Standard, Professional, and soon Enterprise Editions available
Two versions of Deep Freeze are presently available; Deep Freeze Standard Edition and Deep Freeze Professional Edition. An Enterprise Edition is in development and a Windows 2000/XP version is scheduled for release in mid-2003 with a Windows 9x/Me version to follow soon after.

Both the Deep Freeze Standard and Professional Editions come in two versions, one for Windows 95/98/Me and one for Windows 2000/XP—sorry no version for Windows NT. Deep Freeze supports IDE and SCSI drives and FAT16, FAT32, and NTFS file formats, and it can be used to freeze any combination of drives and a mixture of file formats on a single PC.

Deep Freeze Standard Edition
Deep Freeze Standard Edition is the basic Deep Freeze product designed for the individual or organization that needs to be able to freeze a computer's hard drive and restore to a default configuration at reboot. For corporate and government users, pricing starts at $24.25 per license. However, the price goes down the more copies that you buy. For example, if you purchase 5,000 or more licenses, the price is $5.66 per license. Standard Edition is also the only Deep Freeze version available as a single-unit purchase at $59.95 including shipping.

Deep Freeze Professional Edition
Deep Freeze Professional Edition works the same way as the Standard Edition but includes many more features. Deep Freeze Professional also includes the Deep Freeze Administrator, which you can use to create custom Deep Freeze installations for various computer configurations.

Deep Freeze Professional Edition allows you to actually schedule system reboots. By doing so, you can ensure that your designated configuration is restored on a daily basis.

Another cool feature found in the Professional Edition is the idle time reboot. The system can be configured to automatically reboot once the system has been idle for a specific amount of time. As a way of preventing continuous reboots during idle time, the idle time reboot mechanism isn’t activated again until user activity resumes.

Occasionally, you may want your users to be able to make certain changes to the system. For example, if a user saved a document to the local hard drive, you may not want the document erased after the next reboot. This is where the ThawSpace mechanism comes in. The ThawSpace feature allows you to designate anywhere from 16 MB to 2 GB of space as exempt from Deep Freeze. Anything saved or modified within this space will never be touched by Deep Freeze. But this feature has a serious drawback. The space reserved as ThawSpace is a virtual hard drive partition controlled by Deep Freeze. If Deep Freeze is ever uninstalled from the computer, all data stored on this partition will be lost. If you want your users to store information locally it is best to create a separate hard drive partition that you leave unfrozen. Information stored on this partition would not be affected were Deep Freeze to be uninstalled.

You can also designated a ThawTime during which can update your Deep Freeze-protected computers. For example, you could tell Deep Freeze to keep any changes made between midnight and 4:00 A.M. If you are worried about users tampering with the machine during the ThawTime, you can configure Deep Freeze to lock the PC's keyboard, and you can push the updates to the workstations remotely.

The Professional Edition simplifies the installation process as well. You can perform a hands-off installation over a network, simultaneously rolling out Deep Freeze to multiple workstations. The installation process takes anywhere from two to four seconds per PC. There are also some cool new installation options. For example, you can install in stealth mode, which installs Deep Freeze without placing the system tray icon onto the PC. You can also do custom installations that exclude any Deep Freeze features that you don’t want to use.

If you tend to have a lot of computers in your organization, you’ll be happy to know that Deep Freeze can be completely operated from a command prompt. This means that any Deep Freeze commands can be run automatically by scripts that you develop.

Deep Freeze Professional Edition is slightly more expensive than the Standard Edition. Pricing starts at $31.20 per license but drops as low as $7.00 for those who purchase 5,000 or more licenses.

Not for everyone, but perfect for some
Overall, Deep Freeze performed exactly as described and I experienced no problems. Yet Deep Freeze is still not for everyone. I would be cautious about using Deep Freeze across the board in a normal corporate environment. If your PCs aren't configured properly and your end users aren't educated on Deep Freeze's abilities, the potential problems could be serious. (I can hear the irate user now, "But I saved the yearly report to my C: drive. Now it's not there and I need this for the all-company meeting tomorrow.")

I would, however, recommend this product to those who support PCs in an open environment such as public kiosks, Internet cafes, corporate training rooms, or school computer labs. Deep Freeze can reduce the amount of time your help desk spends managing the PCs in these settings.

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