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How to manually uninstall Deep Freeze

for Windows 2K/XP

by Emiliano Scavuzzo


 If you are reading this tutorial you'd probably know that Deep Freeze not always work the way it should and sometimes it can do more damage than good. Some common scenarios include the installer not being able to uninstall DF even when the disks are thawed, Deep Unfreezer not being able to thaw the disks or something worst: the system fails to boot. This tutorial explains how to manually uninstall Deep Freeze by removing it's core driver from the registry and therefore completely disabling it. This tutorial doesn't explain how to do a complete uninstallation, though. There's a lot of garbage Deep Freeze installs on the disk and registry that you'll have to find yourself, but remember that this garbage can't prevent the computer from booting or freeze the disks. You can always try to restore the registry from a point before installing Deep Freeze by using the backups saved on %windir%\repair or System Volume Information.

 This tutorial is intended for advanced users. If you don't even know what the registry is you shouldn't follow these instructions. Playing with the registry is dangerous and you could damage your system by doing so.

Always make backup copies of the registry files before trying this tutorial.


Without a complete uninstallation you may not be able to reinstall Deep Freeze on your system.

Let's get to work:

1.       First we need a way to edit the registry. The way to do this depends on your situation. If your computer is thawed you can simply use Regedit. If your computer is frozen or if it doesn't boot you'll need to find another way. Here are some alternatives:

  • If you have a multiboot computer with another copy of Windows 2K/XP you can boot from there.

  • You can physically mount the disk on another computer that uses Windows 2K/XP.

  • You can use a tool that lets you boot and edit the registry. A good example of this is PE Builder that lets you build a Windows PE CD and boot Windows from there.

Windows XP can import and edit the system hive from Windows 2K (hive format 1.3) but Windows 2K can't import the system hive from Windows XP (hive format 1.5).

2.       If your computer is thawed run Regedit. If it's not thawed follow one of the alternatives described above, run Regedit (or Regedt32 on Windows 2K) and import the system hive. To import the hive highlight HKEY_LOCAL_MACHINE. On the menu go to File or Registry, Load Hive and open the system hive from the control, that should be on %windir%\system32\config (from the disk where DF is installed).

3.       A dialog box will open and you will be prompted to enter a name for the key where the hive will be loaded. We'll use MySystem. If you are using Windows 2K, after loading the hive close Regedt32 and run Regedit.

4.       Highlight the new key HKLM\MySystem (or HKLM\SYSTEM if you didn't have to import the hive) and select Edit and Find from the menu.

5.       On the Find dialog box type UpperFilters and check only the Values checkbox. Then click Find Next.

6.       The program will find a value with the name UpperFilters. Open this value and if there's a line with the name of the Deep Freeze driver (DeepFrz or DepFrzLo) delete it including the return, leaving the rest of the lines intact. Also, if you are using ThawSpace and you want to get rid of it delete that line too (ThwSpace), if you want to keep the ThawSpace leave it there. Press F3 to find the next match and repeat the operation until you have fixed all the UpperFilters values inside the HKLM\MySystem key.


7.       Navigate to HKLM\MySystem\Select and check the value with the name Default. It has the number of the control set key that the system will use when booted. If it is 1 the control set is ControlSet001, if it is 2 the control set is ControlSet002, and so on. We'll assume the control set is ControlSet001 but you should use the one specified by the value Default.

8.       Now go to HKLM\MySystem\ControlSet001\Services and delete the keys with the name of the Deep Freeze drivers (DeepFrz or DepFrzLo and DepFrzHi). Also, if you decided to get rid of the ThawSpace delete the key with the name of the ThawSpace driver (ThwSpace).

9.       That's it. Now reboot and load the system where Deep Freeze was installed and you'll notice you can make permanent changes to disks that where previously frozen.


Stat rosa pristina nomine, nomina nuda tenemus.



Copyright (c) 2005 by Emiliano Scavuzzo - All Rights Reserved