Since AMD stopped support for Radeon HD3xxx there is no official Win 10 driver available. You can try to download the latest Win 8 AMD Catalyst to be found here:
and install it.
To do so start the device manager select the graphics adapter and uninstall it. Afterwards you will have very low resolution but there will be graphics support.
Then select "update driver" (sorry I'm not running the english version of windows so I don't know exactly the name of this button). Then select to search for the driver on your computer and select the downloaded catalyst software. You probably have to try several .inf files in the display-folder if it doesn't work the first time.
After the software has been installed successfully you should be able to start AMD Vision and setup graphics as desired.