Can't change back ground. It just stays grey!!

Hi,
I started solidworks today and the background was just a solidgrey. All the options are still there in the scene menu but when Ichange it the background stays the same. The assembly changes to aslightly darker or light colour but thats it.
Can any one help me with this ?
I did a solidworks repair already and it made no difference.
SolidworksUser Interface