Copying File Failed

I jut download Unity but I cannot open the software.

it appears an error window which is “Copying file failed”

the contents is "

Copying C:/Program Files/Unity/Editor/Data/Resources/Packages/unity-editor-home.0.0.13.tgz to C:/Users/Wai/AppData/Roaming/Unity/Packages/unity-editor-home.0.0.13.tgz: Access is denied. "

There are three options, “Try Again”, " Force Quit" and “Cancel”
However, none of them help me to open the software

I tried to reinstall the software , it failed to help. I also looked up the internet and find out that people mentions to delete the file in AppData. However, the computer said I have no premission to do that.

What should I do? I just want to use Unity~ please help~

Its Usually the space on your Computer, try and free up some space.