Try this. Hold down Shift CRTL Alt at the same time and then hit F6. This should bring up the actual Deepfreeze password box. Do not enter a password at this time. Hit OK to get out of that screen. If this works successfully then you should be returned to your Desktop in a frozen mode. At that time hold down Shift and double click on the white Deepfreeze icon. If prompted for a password click on OK. Next screen should offer you 3 choices. 1=frozen. 2=Thawed for next boot only. 3=permanently thawed. Choose option 3 and reboot. The machine should come up to the desktop with a red X showing on the white deepfreeze icon. If you are successful in getting this far then insert the Deepfreeze disk execute the program and choose the option to uninstall the program. Watch the prompts. The machine will reboot again and deepfreeze will be gone.
Just curious. Why did you install Deepfreeze in the first place?