Try this
Try this.
Orbiter is not installed using an msi or any other type of installer engine. Therefore Orbiter does not have to be installed to the C:\Program Files Directory.
Permissions should not be an issue unless you extract Orbiter while logged in as one user account and then log into another (or create another) and try to access the Orbiter folder in the other user accounts file system unless you create another administrator account (I do not recommend this).
You should have only 1 admin account on any box.
I log into a regular limited user account and then I extract the Orbiter files into a folder I create on the desktop called "Orbiter 2006 P1-01" and then I install the MFDs I want and sound etc.
This way when you want to access the files in Orbiter, its right there on your desktop.
Orbiter is unique in that it doesnt need to "install" on to your computer. Its a program that is contained within the folder you install to.
You do not need to uninstall it from Add/Remove programs because it never installed it just extracted the pertinent files from the archive .zip file to where ever you designate the extraction to be during extraction.
You should create the folder on your desktop first then extract Orbiter's files into that folder and then find the exicutable file "orbiter.exe" and then you can right click and select Send to... and select Desktop. This will create a shortcut and then you wont have to open the folder every time you want to run Orbiter.
To get rid of Orbiter you simply delete the folder and there will be no effect to your system or registry.
You should still be able to grab your folder from your C:...\Program Files\...Orbiter and cut and paste the whole folder to yur desktop with no problem. Your current shortcut wont work so youll have to make a new one as stated above. (i.e right click, send to, desktop)
To delete scenarios, find your Orbiter folder and then the scenarios folder and the name of the file should be visible. Just highlight and then delete.
You should not be in the Orbiter Launchpad when you make changes to the file system of Orbiter. Exit the game and then do what you want to do (i.e. add an MFD or an add-on or delete scenarios), then restart the Orbiter sim.
Good luck and welcome to Orbiter Heaven