Problem installing Puppy Linux

I have a rather old (about 15 years) hp mini and I want to install Puppy Linux. The problem is that the drive partition is 'locked' and I cannot delete it to set up for installing Puppy. Could someone tell me how to unlock the partitions on the hdd? I have tried using gparted but that only shows the partition as locked with no way to unlock. My guess is that there is possibly a way to achieve the unlocking via the command line, unfortunately, I am not very proficient in using the CLI, although I can type and follow instructions and I do know the commands I use regularly. So, as anyone any suggestions as to how I unlock the partitions?

Yours hopefully,

Gael.