I have a PC with Windows 10, upgrade from Windows 7 and a Samsung flat screen monitor with DVI digital input and VGA Analog input. I have a good video card and connected to the DVI input everything was fine. Recently an older friend asked me to install some games on his older Gateway PC with VGA input. I have a VGA-VGA cable. I turned off my PC and. Unplugged my DVI cable from the monitor and plugged in one end of the VGA cable to my monitor, and the other end into my friends VGA input on his PC and installed his games. I then turned off my monitor and his PC and removed the VGA cable. When he left I re connected my DVI cable to the monitor and booted it up my PC, it was running fine but my monitor reported it was in analog mode and check signal cable ? I checked the connection to my monitor it was fine, but the monitor still reported that it was in analog, and check signal cable ?

Suggestions ?