I think you do not need knoppix, only google

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Dell System Recovery Partition Hotkey & Instructions (Dell PC Restore):

To access the recovery partition on your Dell computer for recovery, follow the steps listed below.
1. Power on the computer
2. At the Dell logo, hold the Ctrl key and press the F11 key simultaneously.
2. The Dell PC Restore screen will come up.
3. Select Restore or use the Tab key to highlight it and press Enter.
4. if you wish to continue, click Confirm, or use the Tab key to highlight it and press Enter.
5. When the utility is finished, click Finish, or use the Tab key to highlight it and press Enter.