How to show a window on all virtual desktops
Solution 1:
Do this:
- Have more than one virtual desktops and the window displayed on the current one
- Enter Task View either by the taskbar icon or the shortcut Win+Tab
- Right-click the window and select "Show this window on all desktops".
For more information and screenshots see the article
How To Pin An App Window To All Virtual Desktops In Windows 10.