PC eye is actually the only guy who seems that he doesn't know what he's doing actually. If he can't even delete a partition with an XP disk he isn't much of a tech. Be better off selling furniture.
When Vista was dual booted here and created a folder called "boot" with a subfolder named "en-US" neither XP or a live Linux distro could remove it! The SP1 recovery disk at the time wasn't able to gain access due to the two updated versions of XP being on the drive. That's a common problem seen with permissions and a few other things when trying to access a newer release with newer security features added.
Once you have a good burn of GParted and get up to the gui there the process is simply highlighting the partition shown and clicking on the delete button on the explorer bar followed by the apply button. You will then be prompted to confirm it's deletion. When this is finished click on the red button at the lower left hand side and choose the "reject disk & reboot" option. Once you have removed the disk you simply click on the ok to see the system restart or simply shut it down from there with the power button.