Deep Unfreeze is a software that allows you to disable the DeepFreeze protection when in some case you are forgotting your password. For using this software, just run the Exe, and choose your DeepFreeze version.
For example, click on the Option for DeepFreeze 6 Standard, and Click Apply
After that, double click the DeepFreeze Tray Icon while holding Shift button on the left side of the Keyboard.
Then the DeepFreeze window will appear, and you can now deactivate or activate it without password.
Here is the download links