If your desktop icons disappear without you knowing what happen or if you want hide your desktop icons intentionally. There is option in Windows 10 & Windows 7 that allows you to hide your desktop icons or to show if it's hidden.
Some people select this option accidentally and hide all their desktop icons by simply clicking things they did not intend.
To do this:
1- Right click empty area on your Desktop
2- Click View
3- Select "Show Desktop Icons" option from the popup menu window. It should show the desktop icons if there is a check mark and hide if you remove the check mark.