Problems with iTunes when it is all over the PC screen

I recently downloaded iTunes on my new PC Win 10, Monitor HD 26 inch. When I open the iTunes on all over the PC screen (maximum), and go to iTunes store, under Music or Movies I only see the upper line of products such as new albums, new music but not all the other tracks and not all the records that usually seen all aver the screen. Besides the upper line with new albums, the rest of the iTunes screen is black, however if I click on any point I can open the track. The same is in iTunes store under movies. I only see the New and Nateworthy and Editors' choice but I do not see all movies since the rest of the screen is just black. However, if I change the iTunes screen and reduce the size to almost half of the PC screen, I see everything and all movies and music tracks.

My monitor is HD and I wonder how can I fix this bug.

Thank you for your help.