I am unable to save the picture and sound settings on my Philips TV

You changed some personal settings, but they were reset after you switched off the TV.

Verify if the TV is set to Shop mode. Use the remote control to select: [Setup]>[Installation]>[Preferences]>[Location].

Only the Home mode allows you to change any preferred settings.

Proceed as follows to activate the [Home] mode:

1. Press the [Home] button on the remote control to access the [Home] menu.
2. Use the cursor button to select [Setup] and press the [OK] button to confirm.
3. Press the cursor [Down] to select [Installation] and press the cursor [Right].
4. Press the cursor [Down] to select [Preferences] and press the cursor [Right].
5. Select [Location] and press the cursor [Right].
6. Select [Home] and press the [OK] button to confirm.
7. Press the [Back] button to exit the menu.
8. After you have activated the [Home] mode, you need to switch your TV to standby, in order to make sure that the TV completely exits the [Shop] mode.