Can't switch to dedicated nVidia graphics card

I have an ASUS F552CL laptop with Ubuntu 15.04 installed.

The laptop comes with a dedicated nVidia GeForce GT 710M graphics card.

I have installed and enabled all the proprietary drivers suggested in Software Updates - Additional Drivers:

When I try to switch to the dedicated graphics card using NVIDIA X Server Settings, a message pops up asking me to log out and log back in to apply the changes:

And it looks like the dedicated graphics card has been selected:

However, if I log out and log back in the integrated graphics card shows up as the card in use:

I also tried to reboot instead of to log out and log back in but the integrated graphics card keeps showing up as the card in use.

When I run gksudo nvidia-settings in Terminal, after having closed NVIDIA X Server Settings I get the following message:

ERROR: nvidia-settings could not find the registry key file. This file
       should have been installed along with this driver at
       /usr/share/nvidia/nvidia-application-profiles-key-documentation. The
       application profiles will continue to work, but values cannot be
       preopulated or validated, and will not be listed in the help text.
       Please see the README for possible values and descriptions.

Solution 1:

There is a known bug to nvidia settings: Bug #1341140.

If you receive the following error message, you are probably affected by it:

ERROR: nvidia-settings could not find the registry key file.
This file should have been installed along with this driver at either
/usr/share/nvidia/nvidia-application-profiles-337.25-key-documentation or
/usr/share/nvidia/nvidia-application-profiles-key-documentation.
The application profiles will continue to work, but values cannot be preopulated
or validated, and will not be listed in the help text.
Please see the README for possible values and descriptions.

There is a workaround to this bug, also contained in the bug report. Execute the following from a root shell, replacing the 340.24 by the actual driver number. (I yet have to find out what they mean...)

mkdir -p /etc/nvidia
cd /etc/nvidia
ln -s /etc/alternatives/x86_64-linux-gnu_nvidia_app_profile_keys nvidia-application-profiles-340.24-key-documentation
ln -s /etc/alternatives/x86_64-linux-gnu_nvidia_app_profile nvidia-application-profiles-340.24-rc

Now the problem should be fixed, according to the bug report.

EDIT: The OP mentioned that he had to alter above commands as follows:

cd /usr/share/nvidia
mv nvidia-application-profiles-340.76-key-documentation nvidia-application-profiles-key-documentation
mv nvidia-application-profiles-340.76-rc nvidia-application-profiles-rc