With a blank screen, no code typed into the editor at all, press F4. Anything happen? Errors, etc?
There should have been a quick flash of COMPILATION SUCCESSFUL. If you got a system error at this point, there's probably something wrong with your installation of DarkBASIC or you may be missing some key system files, or the permissions that are set up on the computer are not allowing you access to some files or directory.
If there wasn't an error, with the screen still blank - no code in the editor at all, press F5. If there were no errors, the screen should've blinked and then the CLI window should come up at the bottom.
Where the cursor is flashing, type:
print "Hello World"
the press [ENTER]
Did you get any errors? Hello World should be at the top of the screen.
If everything is ok try typing
box 100,100,200,200
Press [ENTER]
a box should appear on the screen
If everything is working so far try typing
make object sphere 1,25
and press [ENTER]
If everything worked, we just tested 2d and 3d, I'm guessing something is wrong with the permissions on the file system. I think DarkBASIC tries to create a temporary file whenever you execute code from the editor. If the file isn't allowed to be created, that may be causing the error.
Enjoy your day.