Why is display defective after reboot?

[Fidodido1966]

Each time I reboot my PC, many aspects of my display are defective. Few examples include empty context menus after a right click, windows explorer not showing folder or file icons, time in taskbar not changing unless I refresh, etc... If I leave my computer unused for a few hours, everything goes back to normal when I start using it again. I'm on Windows 10 professional 64 bit. It's been going on for months so every graphics driver updates haven't fixed anything. I don't use any graphics card and my motherboard is ASUS B85M-G.