What is the first opening screen on computer called?
That depends on which one you are referring to. It could either
be called the "splash screen" or the "welcome screen". The "splash
screen" is the screen that shows the progress of the operating
system loading. For example, in Windows XP, the splash screen shows
the Windows XP logo, along with a progress bar at the bottom. The
"welcome screen" appears immediately following the splash screen,
and is what allows you to log into your computer after the
operating system finishes booting up.