El Capitan 10.11.5
I just purchased this computer and after changing my desktop to what I wanted, it always changes back to the default after restarting.
Can anyone help?
I have gone through syspref to change and have also used the set to desktop but neither will keep it set.
iMac (21.5-inch, Late 2012), OS X El Capitan (10.11.4)
Have you installed any anti virus , third party apps in your system please clarify .
No anti virus or third party apps.
1. If you log in automatically, a bug in some versions of OS X will cause the desktop picture to revert to the default image at every startup. The only known workaround is to disable automatic login in the Users & Groups preference pane.
2. If the selected Desktop picture is stored in a photo library on an external drive, please export it from the library and move it to a folder on the startup volume. (Credit for this solution to ASC member janay.)
3. If the desktop picture always reverts to a plain blue background, one of your login items may be causing the problem. The "TeamViewer" application can have this effect. Otherwise, rule out all other third-party login items as possible causes.
4. If you have a MacBook Pro with automatic graphics switching, disable it temporarily in the Energy Saver preference pane, set the Desktop picture, then restart the computer and re-enable graphics switching.
5. If none of the above applies to you, proceed as follows.
Back up all data.
Triple-click anywhere in the line below on this page to select it:
~/Library/Application Support/Dock/desktoppicture.db
Right-click or control-click the highlighted line and select
Services ▹ Reveal in Finder (or just Reveal)
from the contextual menu.* A folder should open with an item selected. Move the selected item to the Trash. Log out or restart the computer and empty the Trash.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select
Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.
An apple article is there : Mac Basics: Display a screen saver when you're not using your Mac - Apple Support
Desktop Wallpaper keeps changing back to default
