Stop BOINC running as a service
From BOINC Wiki
Disable running as a service
Uninstall & reinstall BOINC.
In the third screen of the installer, click the Advanced button.
Error creating thumbnail: Unable to save thumbnail to destination
You'll get to the "Customize installations options" window.
Error creating thumbnail: Unable to save thumbnail to destination
On it uncheck Service Install.
File:Install7-4advanced-no-service.png
And click Next to continue the installation.
Return to I have a GPU but BOINC doesn't see it.