There is a privilege called admin in Windows OS, who holds all the controls over Windows. Besides admin, you can create a user(s) who has limited privilege on Windows OS control.
If you have failed to install or update Lunascape, you can think of the situation such as...
At work, they control who can install software into the computer
At home, other users who're sharing the computer has set a control who can install software into the computer
If this is a case, please contact your system administrator to grant you an admin privilege or log in as an admin to proceed the installation/updates.
Installing Lunascape without Admin Privilege:
Lunascape version 6 offers a feature called "Portable Installation," which allows users without admin privilege to install Lunascape.
There are some cases that security software interferes Lunascape installation or update. If this happens to you, please disable the security software while attempting the installation/update.
If you continue experiencing difficulties installing or updating Lunascape, please create a post on the Lunascape Support Forum to further obtain a help from Lunascape Employees or other Lunascape users.