Thank you for raising your concern in this community.
Hello, the three folders you mentioned are system folders and cannot be completely deleted after you have added and saved these folders
- WindowsApps is the path of programs downloaded from the application store
- ProgramFiles is the optional path to save other software installations
- Delivery Optimization file is a folder where the Windows "Delivery Optimization Service" is stored
Based on your current needs, you can actually hide it by right-clicking on any of the folders - Properties and setting it to Hidden in the General Options page.
If anything is unclear, please do not hesitate to let me know.
Best Regards,
Edward - MSFT | Microsoft Community Support Specialist