Error 5 means you don't have permissions to create the "D:\net.downloadhelper.coapp" directory.
It is possible that you do not have administrator permissions or that this directory already exists.
To fix this problem, you can try the following steps:
- Run the installer as an administrator.
- Delete the "D:\net.downloadhelper.coapp" directory if it already exists.
- Restart your computer and try to install the program again.
jerome