SH910 and the computer are in the same domain and I can download Qpresenter from the projector and control the it with virtual panel, but when I want to display the desktop of the computer, it asks me to input password. What is it?

"You can solve this by
1. Disable ""Login code"" in the Network setting in OSD menu.
2. If you wish to use ""Login code"" you can find the password on the up right corner of the screen when you switch to ""Network display"". "