Unerasable folder in the Recovery Partition

I have a Hitachi Touro Pro Backup Disk which contains backup data from a discarded computer. I tried copying the data to a DVD using the replacement laptop (in order to use it on the new computer) but somehow (and I don't understand how) the data wound up in the Recovery Partition (Drive D) of my HP Envy Laptop running Windows 10. When trying to erase this folder I first have to uncheck the ReadOnly box in the Property window. It then goes through an elaborate erasing procedure involving all the subfiles and finally announces that the folder has been erased. The Recovery Partition Property window shows that the unused memory has been restored. However it does not go into the Recycle Bin. Not long thereafter I receive a Low Disk Space warning and on checking the Recovery partition find that the folder has been restored. I have attempted the procedure several times with the same result. How can I finally erase this folder?