|You cannot wipe/format a drive (partiton) while it is being used. |
It sounds like you are trying to wipe the operating system while using it to run killdisc.
The proper use is to have the drive that you wish to wipe clean installed as a slave drive to the operating system that kill disc is installed on. Then remove the partition tables then use kill disc to wipe the drive and set it back up for future use.
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